Yesterday one of my classes was practicing wh- questions in past simple (Stretch Starter, Oxford University Press, p 93). The activity involves creating a question for the given answer. The first is provided as an example, and I've filled in the rest:
1A: Where did you go? B: I went to a movie.
2A: (Who did she come with?) B: She came with James.
3A: (How long did they stay [for]?) B: They stayed for a week.
4A: (Where did Jack go [to]? B: Jack went to Allan's house.
5A: (When did you call [me] [*at]?) B: I called you at 9:00.
For 2, about half the students wrote *'Who did she come?', which is ungrammatical, but I couldn't think why, either on the spot yesterday, or now, 24 hours later. In 3 and 4, the preposition is optional (and unnatural for me). In 5, the preposition is ungrammatical.
Huddleston and Pullum (A Student's Guide to English Grammar, p 137-9) don't discuss it, and I can't find it anywhere else. Has anyone got any thoughts about this?
Best Answer
It is very important to check whether the verb to come is a transitive verb (which doesn't require a preposition) or intransitive verb (which does require a preposition). For example, if you change the interrogative sentence to a declarative one, it will be
It doesn't make any sense. It should be
Therefore, you need the preposition with in the sentence. When "whom" is placed at the beginning as an interrogative pronoun, "who" is more broadly used than "whom".
You need to understand that "how long" and "where" are interrogative adverbs, not interrogative pronouns. Therefore, you don't need to use the prepositions. The same rule applies to "home" as in
You don't need to use "to" in the second sentence above as "home" is an adverb. If you replace home with "where", it would be easier to understand how it works.
"When" is an interrogative adverb which doesn't require a preposition.
You need to differentiate interrogative pronouns such as who, which, what, etc. from interrogative adverbs such as how long, when, where, how, etc.
From time to time, you can hear some native English speakers ask "Where are you at?" or "Where are you going to?" The prepositions at and to are not absolutely necessary, however, they could be used. You can read “Where are you now at?” — grammatically correct? and is “Where are you going to?” correct to understand how they work. They are a few exceptions to the rule.