The Science

7spell is scientifically designed, and utilizes principles based on decades of research in learning, retention, and psychology. Here is a summary of the theory and research behind 7spell's effectiveness.

Craik, F., and Tulving, E. "Depth of processing and the retention of words in episodic memory." Journal of Experimental Psychology: General, Vol 104(3) (1975): 268-294. Print and PDF.

In this seminal study performed at the University of Toronto, Canada, the authors performed a series of tests in which they gave the study participants a sequence of words to learn, with information related to each word as it appeared in order. They discovered that when the information provided stimulated the participant's brain to process the word on a more involved level (referred to as "deep encoding" or "degree of elaboration" in the study), that word was more effectively learned and remembered. With 7spell, the user is given a wide range of additional information about each spelling word, including the word's definition - one of the key factors in enhanced memory, according to this study - as well as usage examples, synonyms, and antonyms.

Garcia, S.M., Tor, A., and Schiff, T.M. "The Psychology of Competition: A Social Comparison Perspective." Perspectives on Psychological Science, November 2013, 8(6):634-650. Print and web.

Each person is influenced by a unique set of factors related to their own status and progress towards goals, but is also affected to a greater or lesser degree by the achievements and perceived standards of the people around them. This analysis of past and current studies looks at the way people view and are motivated by individual goals as well as societal achievement (competition). The authors conclude that effective use of motivational strategies must take both into account. This is something that 7spell accomplishes by providing each user with the ability to set personal goals, earn reward points, and view their own progress tracking reports, and also to publish all of those results on public social media platforms.

Kivetz, R., Urminsky, O., and Zheng, Y. "The Goal-Gradient Hypothesis Resurrected: Purchase Acceleration, Illusionary Goal Progress, and Customer Retention." Journal of Marketing Research, February 2006, 43(1):39-58. Web.

In a study focusing on the influence of reward-scheme programs on behavior, the authors found that when people see visible progress towards their goals they are more likely to increase the activity required to reach those goals. The study also confirms that most people are also motivated by receiving rewards for completing specific activities, even if those rewards are not immediately transferable to actual material or monetary benefits. Status points, rewards, and real-time progress tracking are all methods used in 7spell to encourage frequent spelling practice by awarding points for the completion of exercises and activities. Because the user can access their progress charts at any time, they will always be able to see how close they are to achieving their personal spelling goals.

Buton, M., Winterbauer, N., and Todd, T. "Relapse processes after the extinction of instrumental learning: Renewal, resurgence, and reacquisition." Behavioural Processes, May 2012, 90(1): 130–141. Print and web.

Instrumental learning, also called "operant conditioning," is a method by which behaviors are learned in connection with a stimulus, a reward, or both. In this research done at the University of Vermont, the authors studied the ways in which the information connected to a specific behavior is retained when the stimulus is removed, and how subsequent repetition or reward reinforces information recall and a resumption of previously learned behaviors. They conclude that there are two primary methods of reinforcing active memory and behavior: by creating a different way to test the subject's memory, and by providing the opportunity for intensive focused repetition of that stimulus-behavior response. These two methods are widely used in the 7spell activities and games to create the link between instruction and memory that is so crucial in effective spelling learning on the student's part.

Xue, G., Mei, L., Chen, C., Lu, Z-L., Poldrack, R., Dong, Q. "Spaced Learning Enhances Subsequent Recognition Memory by Reducing Neural Repetition Suppression." Journal of Cognitive Neuroscience 2011;23(7):1624-1633. Print and web. http://doi:10.1162/jocn.2010.21532

In this study comparing long-term and short-term memory, the study authors tested the neural activity of participants as they memorized a set of images. Half of the study participants used massed learning techniques, in which each new image was presented multiple times in a row; the other half were given the images in a spaced repetition mode, where the images were shown in alternating order. Although each participant saw each image the same number of times, the people in the spaced-repetition exercise were able to accurately remember more images, and for a longer period of time. Repetition is a key technique in learning spelling, and 7spell incorporates spaced repetition in two ways. First, the system uses randomized selection of spelling words from the user's current list to populate the activities and exercises, ensuring an interval between word reviews. Second, the system's Word Discover feature provides pop-up instant review of the words on that list, again in random order. By providing users with multiple opportunities throughout the day to read and review their words, 7spell provides all of the benefits of the spaced repetition methodology in its spelling instruction.

Blocki, J., Cranor, L., Datta, A., and Komanduri, S. "Spaced Repetition and Mnemonics Enable Recall of Multiple Strong Passwords." Cornell University Library, January 3, 2015. PDF.

Spaced repetition is a memory training tool that relies on frequent and consistent review of information; mnemonics is a memory technique that involves multiple ways of looking at that information, such as the incorporation of images or story lines. Researchers at Carnegie Mellon University focused on the combination of spaced repetition and mnemonics in evaluating how best to train people to remember specific pieces of information: computer passwords. They found that by combining the two methodologies, the results in both ease of learning and retention were increased. 7spell uses each method separately and together to help users learn and remember new spelling words by using the same words in multiple exercises, presenting spelling words in a variety of formats, and encouraging users to add information related to each word to make a personal connection that helps them to remember that word and its correct spelling.

Five Sets of Commonly-Misspelled Words

When you misspell a word it’s usually easy to catch, whether you use a spell-check program or not. However, there are some sets of words that are so close in spelling – though far apart in meaning – that your eye might not spot the problem, and a spell-check program certainly won’t mark the word as incorrect if it’s the right spelling, but the wrong word. Here are five sets of words that are frequently confused, and explanations of what each of them mean. Practice using the words and spelling them correctly in context, and you won’t make these mistakes in the future.

If something is stationary it’s not moving, but staying in one position. Stationery is the term used to refer to paper and envelopes, often in decorative or matched sets, that are used for writing letters. You can remember this spelling by remembering that you send a letter in an envelope.

Discreet means “subtle, unobtrusive.” Remember this spelling by keeping in mind that if you meet someone on a crowded street your meeting won’t be very discreet. The word discrete describes things that are separate, unique, or not connected to anything else.

A principle is a belief, law, or code that governs people’s actions. The principal reason to not confuse the spelling of these two words (or any of these word pairs) is that it may make people believe that you don’t know your topic very well. Principal means “first, primary” – remember this spelling by remembering that the letter a is the first letter of the English alphabet.

If you cite someone, it means you’re repeating what they’ve said or written. Remember that the word site (a place or location) starts with the letter s by thinking of the word sight, which also begins with s, and that you can go sight-seeing at historic sites all over the world.

A perquisite (often abbreviated in the plural as “perks”) is a privilege or special access allowed to only a select group of people. For example, if you belong to an airline’s frequent flyer group, one perquisite might be the ability to wait for your flight in a separate comfortable lounge at the airport. However, the prerequisite – something that’s required in order for something else to happen – might be that you have to accumulate 100,000 airline miles before you’re allowed in the door. Remember this spelling by remembering the prefix pre- means “before,” and a prerequisite is something that comes before something else.

Why Proper Pronunciation is Important

Although much of our modern-day communication is done using computers or mobile devices, it’s important that you learn how to pronounce words correctly as well as spell them correctly. While our word processing applications and phones are smart enough to tell us when we’re misspelling a word, that’s only useful when we’re writing to people rather than talking to them. Both writing and speech make an impact on people, and if you want to leave a good impression of your knowledge of a topic and your general level of education and ability, you need to practice the pronunciation of a word along with its spelling.

In many ways, knowing how a word is spelled will help you with its pronunciation, and knowing how to pronounce a word correctly will help you remember how it’s spelled. A good example of the connection between the two is the problem of metathesis, the transposing (switching of position) of letters in a word. Here are some examples of words that are often both misspelled and mispronounced due to this phenomenon:

cavalry (CAH-vuhl-ree)
Many people think that this word is pronounced CAL-vah-ree, and so tend to also misspell the word with the v and l transposed (incorrectly as calvary). Cavalry refers to troops of soldiers mounted on horses; Mount Calvary is a place mentioned in the Bible.

jewelry (JEW-el-ree)
Again, the tendency is to pronounce this word JEWL-er-ee, and spell it accordingly.

nuclear (NEW-klee-uhr)
A recent American president became notorious for his pronunciation of this word as NEW-kyu-luhr – it’s possible he tried to spell the word as nucular as well.

From the examples above, you can easily see that the right spelling will help you with the right pronunciation of a word. While most people will understand what you’re trying to say even when you do mispronounce a word, there are times when your meaning will be unclear, and this will lead both to misunderstandings and the impression that you’re not as capable or knowledgeable as you really are.

On the other hand, an occasional mispronunciation happens to everyone – there’s even a word to describe it: spoonerism. Named after a 19th-century English church leader named William Spooner, this word refers to a metathesis between two words rather than within one word, and only when spoken. Two famous examples of spoonerisms are from television broadcasts in the early 20th century, one where an announcer mentioned a “hypodeemic nerdle” (rather than a hypodermic needle), and another with an announcer’s statement that “All the world was thrilled by the marriage of the Duck and Doochess (Duke and Duchess) of Windsor.”

Malapropism happens when completely different word is used, often one that has similar pronunciation but not the same meaning, so that the sentence makes no sense. Shakespeare used malapropisms for comic effect; a good example comes from the lines spoken by the character Dogberry in Much Ado About Nothing, when he says that he and the other watchmen have captured “two auspicious persons.” Naturally, he didn’t mean that these persons would bring good fortune (the definition of auspicious) but rather that they were suspicious; that is, suspected of doing something wrong.

Watch your words, and your pronunciation, and no one will be suspicious that you don’t have a good command of your topic, and the English language.

Cross-posted on The Vocabulary Builder’s Blog.

English Spelling Essentials: More Rules of Pluralization

In the last post, we covered some of the common spelling rules and exceptions for making English words plural. Today, we’ll look at more of these rules and give examples to help you understand when they apply.

Note: Remember that there are exceptions to every spelling rule, and these are only general guidelines.

If the word already ends in S, add ES to the end of the word.

kiss / kisses
campus / campuses
abyss / abysses
loss / losses
atlas / atlases

If the word ends in IS, change the ending to ES for the plural form.

analysis / analyses
axis / axes
hypothesis / hypotheses
oasis / oases
parenthesis / parentheses

If the word is an irregular plural, you just have to learn it!
We’re not listing all of the words with irregular plurals, but these are some of the most common ones, and ones that give people the most difficulty in spelling:

woman / women
alumnus / alumni
sheep / sheep
fungus / fungi
child / children
tooth / teeth
radius / radii

One final note on plurals: there are many words that we’re used to seeing mostly in their plural form, and often people make the mistake of thinking that the word is actually singular. A good example of this is the word media, which is the plural of the word medium. Because many people refer to “the media” while thinking of the idea of news or broadcasting as one whole entity, they assume that the word is singular. However, you should remember that television is only one medium by which news is broadcast. Some other words that get confused this way are data (the plural of datum) and criteria (the plural of criterion). This last word is often misused in a work environment.

Other words appear most often in their singular forms, and people are often unsure of the correct plural form. Examples include maximum (plural: maxima), memorandum (plural: memoranda), and addendum (plural: addenda).

Do you have two or more questions about plurals? Leave them in the comments.

English Spelling Essentials: How to Make Words Plural

Making a word plural in English is easy – you just add an s to the end of the word, right? Well, yes … and no. Many words do follow this simple rule, but often the addition of an s on the end of a word changes the way that word is spelled. Like many rules, there are exceptions, but in this post we’re going to cover some of the basic guidelines for the times when a word’s spelling changes. Learn these guidelines for use in most cases, and make a note of any exceptions you come across (we’ve listed some of the common ones).

If the word ends in an O (with a “long o” sound), add ES to the end of the word.

mosquito / mosquitoes
cargo / cargoes
motto / mottoes
potato / potatoes
tomato / tomatoes
echo / echoes
hero / heroes
volcano / volcanoes

Exceptions: piano, solo, torso, alto, soprano, silo, studio, and cameo only take an S.

If the word ends in an Y after a vowel, just add S. If the word ends in a Y after a consonant, or with the letter cluster quy, change the Y to IES.

spray / sprays
yesterday / yesterdays
cowboy / cowboys
toy / toys
monkey / monkeys
valley / valleys
turkey / turkeys

quandary / quandaries
ally / allies
steady / steadies
country / countries
party / parties
industry / industries
soliloquy / soliloquies
obsequy / obsequies

If the word ends in a single F or in the letters FE, the plural is VES. If the word ends in FF, just add an S.

knife / knives
shelf / shelves
life / lives
thief / thieves
wife / wives
leaf / leaves

fluff / fluffs
plaintiff / plaintiffs
staff / staffs

Exceptions: There are rather a lot of exceptions in this category! Here are a few of the ones you’ll see most often. These words are pluralized by adding an S.

giraffe, chief, surf, hoof, roof, gulf, grief, belief

We’ll go over more rules and exceptions in the next post.

Spelling Fundamentals: Suffixes

In a previous post, we talked about prefixes, which are groups of letters that are added to the beginnings of words to changes those words’ meanings. When a prefix is added to the stem word, it does not change that word’s original spelling (read this post to review prefixes).

A suffix is added to the end of a word in the same way, but unlike prefixes, suffixes often change the spelling of the stem word. To add to the confusion, the way the stem word changes depends on the letters involved – both the letters ending the stem word, and the letter beginning the suffix. Because this aspect of spelling in English is very complicated, we’ll be taking a bit of time to look at suffixes in detail.

Note: There are exceptions to every rule of English spelling – we’re just giving the most common examples here.

-able and -ible

The suffix -able means either “able to be [stem word]” or “able to do [stem word].” For example, the word desirable means “able to be desired” (or “capable of being desired”). Notice that when you add the suffix -able you change the spelling of the stem word desire by dropping the e.

desire + able = desirable

The general rule is that you use the suffix -able in most cases, dropping the final e at the end of the stem word, if necessary. Here are some more examples:

remark + able = remarkable
afford + able = affordable

In general the suffix able is added to a stem word that can stand by itself. The alternate spelling -ible has the same meaning, but is combined with root words to form new meanings; these root words are most often not English words when taken by themselves. Here are some examples:


When the stem word is noun ending in ion, use the suffix -ible.


When the stem word ends in ation, use -able.


Notice that you are replacing a set of letters with the suffix to create the new words.


By adding the suffix -ly to a stem word, you create an adverb.

critical + ly = critically
quick + ly = quickly
confident + ly = confidently

If the stem word ends in a consonant plus the letters le, you already have the l, so change the final e to a y.

gentle + ly = gently
simple + ly = simply

If the stem word already ends in a y, change the y to an i and add the suffix.

hasty + ly = hastily
crazy + ly = crazily
funny + ly = funnily
angry + ly = angrily


The suffix -ous is used to turn nouns into adjectives. If the noun ends in ge (pronounced with the “j” sound) then add the suffix without changing the spelling of the stem word, in order to keep the correct pronunciation.

courage + ous = courageous
advantage + ous = advantageous
outrage + ous = outrageous

For almost all other stem words, drop the final letter if it is a vowel, but otherwise leave the spelling of the stem word alone.

adventure + ous = adventurous
poison + ous = poisonous
fame + ous = famous
humor + ous = humorous
virtue + ous = virtuous

What Are Prefixes?

Prefixes are units of meaning that are attached to the front of a word to change its definition. The word prefix itself contains a prefix: pre-, a Latin root meaning “before.” Prefixes come before the main word; a suffix comes after the main word. Both prefixes and suffixes are types of affix (pronounced AH-fix), a linguistic term for something attached to a word or another part of a word (the verb affix, here pronounced uh-FIX, means “to attach”).

Prefixes are added to the main words (also called “stem words”) but don’t change the spelling of those words. This can cause a problem in spelling when the prefix ends with the same letter that starts the main word. One of the most common occurrences of this is with the prefixes dis- and mis-. Even when adding the prefix causes a doubled letter, don’t change it. Both the prefix and the main word are independent bits of information. A good example is the word misspell – you are mis-spelling the word if you only use one s.

Mis- is a prefix that means “wrong” or “off target.” If you are walking through your house in the dark, you might misstep and accidentally put your foot on your dog’s tail.

Dis- is a prefix that means “apart from” or “not.” If you are not happy with the food you’re served in a restaurant, you are dissatisfied with your meal.

The doubled-letter problem is most often an issue with a prefix ending in s, but as long as you remember that the addition of a prefix does not change the spelling of the main word, you won’t have any difficulties. Here are some other common prefixes and their meanings:

Trans- means “across.” Before the invention of the airplane, you had to take a transatlantic voyage to get between New York and London.

Two prefixes that are often confused are inter- (“between, among”) and intra- (“within, into”). To help you remember which is which, think of the words interview (an interaction between two people) and intravenous (something injected into a vein).

Another often-confused pair of prefixes is ante- and anti-. The first one means “before”) – think of the words antebellum (“before the war”) and antecedent (“previous, coming first”). The more common prefix anti- is easier to remember; it means “against.” To fix this prefix in your mind, think of the words antiseptic (“against infection”) and antisocial (“disliking being with people”).

Prepare yourself by perfecting your prefixes, and you’ll find that your ability to correctly spell words will continue to improve in precision.

Spelling Tips: -CEDE vs. -SEDE vs. -CEED

When we’re talking about words that end in the letter combinations -cede, -sede, and -ceed, one fact should supersede all the others: the word supersede is currently the only English word that ends with -sede. This word is a verb meaning “to take the place of” – and it’s possible that over time the spelling supercede may supersede the current spelling (some dictionaries now show both versions). However, for now we recommend that you use the correct spelling, and use -cede for words such as precede, secede, concede, recede, etc.

Why is there this difference in spelling? The answer is in the history of the words (their etymology). Supersede comes from the Latin prefix super- (“above”) and root word sedere (“to sit”). Traditionally, someone who “sits above” someone else replaces them in authority or position. All of the other words that end in -cede derive from the Latin root word cedere instead, which means “to go.” Therefore, adding prefixes to this root we get “to go before” (pre-), “to go apart” (se-), “to go back” (re-), and so on. In general, other than the word supersede as discussed above, any word that ends in the sound SEED is spelled with -cede.

Of course, since this is the English language there are exceptions to this rule. These three words are spelled -ceed instead:

Although these three words also come from the Latin root word cedere (proceed = “to go forward” / exceed = “to go above” / succeed = “to go after”) their spellings are different. This is due to the fact that they became part of the English language at about the same time, in the 14th century, and so were all governed by the rules of spelling in Old French. Words such as precede were later added to the English language from Middle French, which had different spelling rules.

We hope we’ve planted a few “seeds” of curiosity in you about word origins and their connection to spelling!

Twelve Words That Are Frequently Misspelled

When you make mistakes in a word’s spelling, there are many possible outcomes, and none to your advantage. If you’re a student, you might get marked down for those errors and get a lower grade. If you’re writing a business letter or other communication that is shared with other employees or clients, the people reading those documents will wonder if you truly know the meaning of the words you’ve misspelled, and may begin to doubt your competence. Worst of all, if you’ve misspelled words in a letter of application or your resume or CV, you might miss your chance at that job in the first place.

With that in mind, we encourage you to check your spelling as part of any review you do on a document before it leaves your hand. Don’t rely on the computer’s spell-check program! The computer won’t know the difference between their and there, and even the simplest mistake will draw attention away from the content of your writing. We’ve collected twelve words that often cause the most problems for people, and hope that you’ll take the time to memorize their spelling. If you’re studying for the GED or for a college entrance examination, you’ll undoubtedly encounter at least half of these words on those tests.

Practice spelling out the words several times to allow your muscle memory to assist the process of committing these words to memory. If you are unsure of the word’s definition, look it up, and come up with at least one sentence using the word. Finally, make sure you know the correct pronunciation of each word. People who don’t know how to pronounce a word are more likely to misspell it.

Remember that there is A RAT in separate.

Pronunciation is key here: say PRO-bab-ly, not PROB-ly, and you’ll get it right.

Again, if you know this word is pronounced TEM-per-a-ture, instead of TEM-pra-ture, you’ll avoid making a mistake in spelling it.

The SC combination often confuses people, but if you remember that the word SCIENCE is the last part of this word, it will help you spell it correctly.

Practice spelling this word, paying close attention to the ICI cluster in the middle.

Don’t forget there’s a C after the A in this word; this causes problems for many people because it’s not pronounced separately from the Q.

Here’s another cluster to watch for: make sure you include ILI in the middle of the word, and give the words its correct pronunciation of aux-I-li-ary.

One more tricky cluster in this word – watch out for the OUO sequence at the end.

This word is pronounced like the word KERNEL, but its spelling is different. Study both words and make sure you can use them correctly in context.

Remember to double the R in this word.

The double M in this word is important.

PHL is pronounced like FL in this word, but don’t spell it that way. Words like this with three or more consonants in a row are difficult to spell, but once you’ve learned them, almost impossible to forget.

How to Use a Dictionary to Improve Your Spelling

You probably use computers, iPhones, and text messaging to write many of the things you formerly would have hand-written or typed on a typewriter (and if you’re not in your 30s or older, it’s possible that you’ve never even seen a typewriter!). Each of these electronic devices and applications have built-in spell-check systems to help you avoid misspelling words; word processing applications even have built-in grammar-checking functions to keep you from writing an ungrammatical sentence. While these features are useful, they can also be detrimental. If you’re never required to correct your own spelling, you might never learn the correct spelling of a word. That’s why we recommend that you turn off the “autocorrect” feature of the spell-check function on any word processing application you use, and correct yourself as you type. This way, the words you misspell will be highlighted, but the system won’t automatically replace them with what it thinks is the right word.

Back in the days before spell-check, people had to use a dictionary to look up the correct spelling of a word. Many good dictionaries now have websites that are easy to use and provide the information you need at a moment’s notice. If you use a print dictionary, make sure you have a relatively new version, because words are constantly added to the English language, and their meanings and usage also evolve over time. Even the spelling of words can change; for example, some dictionaries now say that alright is an acceptable spelling of all right (as in “It’s alright if your friend eats dinner with us”), though we disagree. However, in time even this altered spelling may be added to the OED and become part of the “official” English language.

A good dictionary will give you the phonetic spelling of the word, showing you where the word breaks into syllables and how to pronounce the word. Learn to pronounce words correctly, and you’ll improve your ability to remember how to spell them. When you mispronounce or misspell a word, your listeners and readers will assume that you don’t know what it means, either. By using a dictionary, you’ll find all the information you need to thoroughly learn a word. Look for these features of a print or on-line dictionary:

– a breakdown of the word into its component syllables
– a phonetic spelling of the standard pronunciation of the word
– which part of speech the word belongs to (noun, verb, etc.)
– the different definitions for the word
– usage examples for each definition
– the etymology of the word
– synonyms, antonyms, and other related words and concepts

Seeing Double: How to Spell Words Correctly

Doubled letters in a word cause spelling problems, in part because there’s usually no difference in the word’s pronunciation from the duplication. With many of these words, you need to simply memorize the correct spelling, writing out the words several times until you’ve locked the word firmly in your mind and fingers. Here are some of the words that are frequently misspelled due to their doubled letters – or lack thereof. Test yourself and see if you can identify which of these words are misspelled:

1. comittee
2. fullfil
3. neccessary
4. occassionally
5. occured
6. personel
7. possesion
8. sherrif
9. travelling
10. vaccuum
11. withold

As a matter of fact, all of these words are spelled incorrectly; either a letter that should be doubled isn’t, or one that shouldn’t be is. Here are the correctly-spelled words, and some tips on how to remember the right way to spell them:

committee (kuh-MIH-tee)
With two Ms and two Ts, you’ll spell “committee” with ease.

fulfill (full-FILL)
You don’t need to be filled full to be fulfilled – only double the second L.

necessary (NEH-seh-sair-ee)
It’s not necessary to double the C when you’re spelling “necessary.”

occasionally (uh-KAY-zhun-uh-lee / oh-KAY-zhun-uh-lee)
Sadly, no: you don’t double the S or the N in this word.

occurred (uh-KURD / oh-KURD)
Both the C and the R occur twice in the word “occurred.”

personnel (PER-suhn-ELL)
Each PERSON on the New Employee List is part of the company’s PERSONNEL.

possession (puh-ZEH-shun / poh-ZEH-shun)
”Possession” possesses two double Ss.

sheriff (SHEH-riff)
Bar the second R, or the sheriff will put you behind bars.

traveling (TRAH-vuh-ling)
Pack light when traveling, and don’t double any of the letters in this word.

vacuum (VAH-kyum)
When you think of empty space, remember it’s an Unlimited Universe out there!

withhold (with-HOLD)
You pronounce both halves of this word as if they’re separate words, so they both need their letter H.

What words make you see double? Tell us in the comments.

Cross-posted at The Vocabulary Builder’s Blog.