Often, the nature of issues in student writing are more complex than just spelling mistakes. We're pretty lucky that most word processors include spell checkers which pick up on unintended extra letters or recognisable spelling errors. One thing that spellchecks can't pick up on is collocation. 'Collocation' is a grammatical term which refers to the usual position of words in relation to other words. As a simple example, consider the following sentence:
I watched TV until 2:20am.
Here, the collocation watch/TV is much stronger than a variation on it, e.g. I saw the TV until 2:30am.
While the example above is very basic, the premise applies to other vocabulary... Vocabulary which may be specific to your discipline and if misused, may cause difficulty for the reader in 'getting your point'. It is reasonable therefore, that if your expression is not as clear as it could be, your marks will be affected. Unfortunately, word processors don't tend to advise on your choice of words, so applying this is your responsibility when writing and proofreading.
- Think about how you've seen the vocabulary presented in the texts you've read. Look for patterns. Which words usually follow, or come before key vocabulary?
- Identify key vocabulary in the title, and consider the different ways in which it can be phrased. It is likely that you will want to use as many of these as possible to try to avoid repetition in your work.
- When proofreading your work, think about your choice of words. Do they make sense?