Despite what you might have seen in the movies, you don't actually need to worry about the living dead, that is unless you're trying to write well.

According to Geoffrey Pullum, a linguistics professor and co-author of The Cambridge Grammar of the English Language, our world is full of zombie rules. "Though dead, they shamble mindlessly on," he warns.

Worrying about these out-of-date grammar rules wastes time and energy, and in the worst case renders your writing stuffy, overly complicated, and less effective. What are they? The Guardian's Style Guide author David Marsh compiled the ultimate list, but here are the basics so you can stress less and write better.

1. Split infinitives.

Actually, unless you're composing that memo in Latin, it's perfectly fine to insert a word between "to" and the verb if that sounds right to your ear "Adverbs should go where they sound most natural, often immediately after the to: to boldly go, to personally guarantee," insists Marsh.

2. Prepositions at the end of a sentence.

Blame 17th century poet John Dryden for this one. He was wrong then and he's wrong now (again, unless you're writing in Latin). "To whom are you going to speak?" sounds insane because, in English, it is. Just write, "Who are you going to speak to?"

3. Double negatives.

Language snobs got themselves in a ruffle when Mick Jagger sang, "I can't get no satisfaction," but Marsh sides firmly with the Rolling Stones front man. "Multiple negatives add emphasis," he writes. "Literature and music abound with them." They're "not Standard English," he allows, but "no native English speaker is likely to misunderstand."

4. Starting a sentence with a conjunction.

A conjunction is a joining word like "and" and "but". Your English teacher may have told you it's wrong to start a sentence with one. Marsh, the Beatles, and William Blake would all beg to disagree. This is another zombie rule that should rest in peace.

5. Try and

Is 'try to' preferable to 'try and' as many of us have learned? "'Try to' has traditionally been regarded as more 'correct' and 'try and' as a colloquialism or worse," concedes Marsh, but while 'try to' is undoubtedly more formal, 'try and' is perfectly fine too.

"Sometimes there is a good case for try and - for example, if you want to avoid repeating the word to in a sentence such as: 'We're really going to try and win this one,'" he adds.

Which grammar rules are still alive and kicking?

Just because a great many so-called rules deserve a stake in the heart, doesn't mean you should take things too far and start playing totally fast and loose with language, however. There are just as many grammar rules that get too little attention as those that get too much.

In his complete post, Marsh also list five rules most of us should really worry about more, like the distinctions between 'who' and 'whom', and 'that' and 'which'. Or check out this Australian writing professor's rundown of her personal "hateful eight" of common grammar errors.