One of the reasons that English is full of easily-misspelled words is that it’s the end product of a thousand years of evolution and incorporation. Words have been added and changed, pronunciation has changed but spelling hasn’t, or the other way around. Words that used to be pronounced phonetically (every letter sounded out) aren’t, yet all of the letters are still there in the same order, and that order – the accepted spelling of the word – still needs to be learned.
Even the individual letters can be confusing, because, unlike Japanese (for example) the five vowel sounds a e i o u have many more than five ways they can sound out loud, and even consonants have different variations. Linguistics specialists have words to describe all of the different ways vowel and consonant sounds are pronounced, talking about things like a “voiced interdental fricative” (the ‘th’ sound in the word “then”) or a “voiceless alveopalatal affricate” (the ‘ch’ sound in the word “church”), but you don’t need to know all of the specific terminology used to talk about these different sounds. You just need to know that there are different ways of pronouncing the same letters or letter combinations, and how that affects your grasp of the correct spelling of a word.
Knowing the correct pronunciation of a word, and using it when you say the word out loud – or even to yourself as you’re reading – will definitely help you keep track of the correct spelling. For example, read this sentence out loud: “I find it intresting that the goverment requires strickly hygenic practices to be followed in its labratories.”
Did you notice any misspelled words in that sentence? Or did the fact that your pronunciation probably matched the misspellings let you ignore them? Read the sentence again, and pronounce the words as they are spelled, with the corrected spellings: “I find it interesting that the government requires strictly hygienic practices to be followed in its laboratories.”
Be careful of your pronunciation, and you’ll improve your spelling at the same time.