Teacher Discussion Forums

Could anyone, please, help me out with this phrase? When I use it, I always add an infinitive afterwards. However, there are plenty of examples on Google where it is followed by the base form of the verb. I've grabbed my Michael Swan book (Practical English Usage) to see if it had anything to say on this matter, but I haven't found anything.
Would this phrase be like one of those verbs that can be followed either by infinitive or the base form of the verb without making any difference in the meaning?

Thanks for your help in advance.

I don't know the "rule" but the best thing to do is ask a native speaker. (I can also accept the best thing to do is to ask a native speaker. In fact, the second one sounds more correct, but I'd probably use the first one. Go figure. )

The best thing to do is (to) realise that the two are equally acceptable and completely interchangeable, with no difference in meaning. The worst thing to do is (to) assume that one form must be somehow "better" than the other.

This is a well known interchangeability and the usage without 'to' is considered as more idiomatic english as confirmed by Lorikeet's preference. As for the "rule", it is a peripheral aspect and not part of core grammar.

Could anyone, please, help me out with this phrase? When I use it, I always add an infinitive afterwards.

You are right in doing so. A to-infinitive functions as a noun, not the bare infinitive (the base form of the verb).

The form without the infinitive appears to be about two and a half times as common. I've just done some sample searches on Google.

I would say it is probably a matter of free choice - I don't think there is any difference of register or formality.

Many thanks for your replies!