I have an advanced student who said that she feels that something I wrote needs a ‘to’ immediately before the word ‘do’. I told her that I don’t know a grammar based explanation, but that I’d find one.
This is the sentence:
This is an indirect way of suggesting that someone not do that.
She feels it ought to say 'not to do that'.
I read the answers to '“Why not do it” vs “why not to do it”'. But it seems to me mine isn't answered in this thread.
Your advanced student is wrong.
This is an indirect way of suggesting that someone not do that
Above, the subject of the second do in the that clause is someone.
This is an indirect way of suggesting that someone not to do that
Above, what your student said changes do into an infinitive. This means it takes over a noun function, and changes do from verb to noun.
After that change, the phrase after that is missing a verb. For this to work, the sentence needs a verb added, like:
This is an indirect way of suggesting that someone is not to do that
Suggest (like command and require) may take a "that" clause where the verb is in the base form, eg:
I suggest that he do this.
(Some people - more in British than American English, I think - use the present: I suggest that he does this. Historically what I've called the base form is a present subjunctive, but since the present subjunctive is indistinguishable from the base form for every verb in the language, I find it an unnecessary complication to give it a special name).
Command and require can also take an to-infinitive clause:
They commanded him to do that.
as an alternative to the that clause
They commanded that he do that.
but this option is not usual for suggest. There is no particular reason why not: it just happens to be a fact about these verbs in current English.
