It already sounds scary, right? Split infinitives -- they're a grammar no-no, but most people have no idea what the heck they are. Some writers wouldn't even know one if it fell right out of their own books. The truth is, most people write with split infinitives. Try to observe this outdated grammar rule, and I can just about guarantee that you'll make yourself crazy.
Splitting Infinitives, and Other Grammar Rules to Ignore
My favorite example of a split infinitive is to boldly go. It's a common phrase, thanks to Captain Kirk, and by strict rules of proper English it's totally wrong. An infinitive is an unmarked form of a verb -- and go is a verb. You split an infinitive when you put an adverb between the verb and its companion to.
Need some examples? Split infinitive look a little something like this:
To quickly walk
To forcefully push
To uncharacteristically yell
Any of these phrases might appear in a sentence that reads well, and sounds correct:
I didn't mean to quickly walk past the library.
You just have to forcefully push it open, that's all.
I wasn't ready for you to uncharacteristically yell at me like that.
Anything wrong with those sentences? Most people would think no, but technically they're all incorrect because they've all got split infinitives. To make them correct, you'd have to re-phrase them:
I didn't mean quickly to walk past the library.
I wasn't ready for you, uncharacteristically, to yell at me like that.
And if you were going to clean up Kirk's dialogue? He'd be saying boldly to go instead...and really, that just doesn't have the same ring to it at all.
Some professional editors despise split infinitives, and in very high-toned academic writing they might be frowned upon. But the fact of the matter is, most writers split their infinitives. Start looking, and you'll find them in everything from blogs to novels to movie scripts. Trying to write without split infinitives can actually make sentences more cumbersome and clumsy, which is exactly what you don't want.
You should always write the way people talk to make your books readable, and most people talk in split infinitives. So forget this grammar rule, and split away. In fiction writing, split infinitives are practically expected.