What’s an infinitive and why aren’t you supposed to split it?

When people find out what I do for a living, they often ask me a grammar question. I’m never quite sure whether it’s to catch me out, or whether it’s something that’s been bothering them for a while but they haven’t got round to googling it.

This happened again when I was at a party on Saturday.

“So you teach writing?” asked the fellow guest. “Tell me this – what’s a split infinitive and what’s so bad about it?”

I was delighted to be asked this and, having had a couple of glasses of wine, probably went on a bit longer and in a bit more detail than necessary. Sorry about that.

An infinitive is the basic form of a word and you can spot it because it has “to” in front of it. Examples are “to laugh” “to want” and “to win”.  It’s the pure form before you start to change it according to tense (laughed/was laughing) or who is doing it (I laugh/ he laughs).

 A split infinitive is when you insert another word between “to” and the verb you are using.

So examples of a split infinitive are “to loudly laugh”, “to really believe” or “to easily win”. The most famous one, familiar to all Star Trek fans, is “to boldly go.”

The reason that this is supposed to be so bad goes back to the roots of our language. The infinitive in Latin is a single word – for instance the Latin for “to believe” is credere (from which, incidentally, we get words like credible). But this can’t be split so grammar purists decided English shouldn’t either.

So can you split the infinitive? My view is that if a split infinitive makes the sentence sound better then it’s OK to do it occasionally.  However, don’t overdo it, especially in a formal document, as there’s a risk you might annoy your reader.

If the sentence is going to sound just as good either way, then I’d suggest you rearrange your sentence to avoid it. For instance, you could write “we are going to win easily” rather than “we are going to easily win.”  Sometimes rearranging won’t work, so you might need to rejig the sentence a little more.

It’s something to always check when you’re editing your document – or should I say, it’s something to check each time you’re editing your document.