How to use not only A but B

Question

Can someone explain the grammatical reason behind why I need to put "to" between also and people in the sentence below

First, it does harm to not only people who are smoking, but also people who are not smoking.

I really appreciate your help.

Answer 1

Hi Mako, I have two ways to explain this, a very grammatical one and a more informal one. I'll post both in the hopes that at least one of them makes sense!

Grammatical answer: There are two direct objects in this sentence, meaning there are two subjects that are being affected by the main verb of "doing harm". You indicate what is affected by the verb using the word "to". Since "people who are not smoking" is also a direct object, it also needs to be preceded by the word "to". I hope this helps!

Informal answer: The reasoning for this is that there is an implied phrase going on in that second part. What I mean by this is that a long (and redundant) form of this sentence is: "First, it does harm not only to people who are smoking, but it also does harm to people who are not smoking." The italicized portion isn't needed because it is implied from earlier in the sentence. But, because it could be there, it only makes sense if the word "to" is included.

Answer 2

The phrase “cause harm” requires the preposition TO , and cannot exist separately in a sentence, with the exception of the place at the end of the sentence “without causing harm.” In the sentence “Smoking causes harm not only TO smokers themselves, but also TO non-smokers.”requires the use of double “to” because it replaces the use of double “causes harm.” According to the rules of Stylistics, we avoid tautology in repetition, but also according to the rules of Grammar, we must use the double “TO” preposition which balances both parts of the sentence. There are many examples with prepositional verbs: listen to, be ready to, pay attention to , and go on.

The phrase “ cause harm” is prepositional phrase and requires TO in mayor cases.