Learning 'spelling rules' is a great way to avoid common spelling mistakes, however, there will always be exceptions to these spelling rules. Further to this, there will no doubt be one or two words that you will never get the hang of. My two worst words which I just can't remember how to spell no matter how hard I try are achievement (I spell it it acheivement) and definite (which I spell definate), I find this very frustrating!
A good way to combat this it to create your own dictionary. As you go through your work, you can pick out words that you find difficult to spell and add these to your dictionary. This will help you to remember words, and act as a reference for those words you just can't remember.
It is especially important that you spell any technical words from your subject correctly. If you are writing an essay and you spell non-technical words incorrectly, you just look like you can't spell, and you will only loose a few marks. If, however, you spell words related to your subject incorrectly, it will look like you don't know your subject properly and you will lose many more marks. You may therefore find it useful to add technical, subject-specific words to your dictionary.
Keep your dictionary with you and use it as a reference when you are writing, especially if you're writing by hand. Try not to be lazy and use spell check, as you won't remember how to spell the words. If you use your dictionary you will learn to spell each word in no time!
1. Buy a notebook or open a word document on your computer and save it as 'dictionary.'
2. As you go through your work and find words that are difficult to spell, for example, words that are repeatedly picked up by your spell check, add these to your dictionary.
3. You can make a note of the rule applicable to each word if this helps you.