As a general rule, the last person you should be consulting while writing is a grammarian. Usage guides? Certainly. But grammar? If you haven’t learned it by the time you’re starting your novel, chances are it’s too late. One goes to war with the army one has.

But in case you are still anxious about your usage, a good tonic for the nerves is Geoffrey K. Pullum’s The Truth About English Grammar. Per Steven Poole’s light-handedly scathing take in The Guardian, Pullum is not the kind of linguist who delivers finger-wagging lectures on tense or how the Internet is ruining the King’s English. Instead, his book appears to be a broadside directed at the grammatical snoots who Pullum thinks have no idea how English is used in the real world:

Readers are meanwhile reassured that there’s nothing necessarily wrong with the passive, or the split infinitive, or the dangling participle, or adverbs. Pullum is an engaging and friendly writer, always on the side of the ordinary Joe against the nitpickers. A particular delight is how he shows that many “rules” beloved of self-appointed grammar constables were simply made up quite recently by irritable ink-stained wretches…

Now, off you go. If splitting a few infinitives means you have the time to figure out what your protagonist is going to do next, then split away.