Word-processing programs usually have a spell-checker, but you should still carefully check for correct changes in your words. This is because automatic spell-checkers may not always understand the context of a word.
Misspelling a word might seem like a minor mistake, but it can reflect very poorly on a writer. It suggests one of two things: either the writer does not care enough about his work to proofread it, or he does not know his topic well enough to properly spell words related to it. Either way, spelling errors will make a reader less likely to trust a writer’s authority.
The best way to ensure that a paper has no spelling errors is to look for them during the proofreading stage of the writing process. Being familiar with the most common errors will help you find (and fix) them during the writing and proofreading stage.
Sometimes, a writer just doesn’t know how to spell the word she wants to use. This may be because the word is technical jargon or comes from a language other than her own. Other times, it may be a proper name that she has not encountered before. Anytime you want to use a word but are unsure of how to spell it, do not guess. Instead, check a dictionary or other reference work to find its proper spelling.