Your knowledge of grammar can influence your style and syntax, and most of all your control of the language!
All translators/interpreters should have a strong grasp of grammar or, if uncertain, should know where to obtain information on the subject. Having grammar books and websites to hand are key to ensure accuracy, as gut instinct is not always correct. Translators/interpreters should be able to justify their use of language, even if there is more than one solution.
Suggested below is a short list of grammar guides and specific linguistic reference books. Everyone has a favourite, therefore you should browse through them to find which is best suited to you.