I'm studying prepositions in questions and faced with the problem.
Where have you been?
At a meeting.
Who / be / you / with?
I'd like to write Who was with you? which looks as one correct way for me (similar to my native language). But, according to the sentence Prepositions in questions usually come in the end. is it possible to write like Who was you with?.
Which one is correct and more preferred (if two are)?
"Who was with you?" and "Who were you with" are equally grammatical and natural, and carry only a very slight difference in meaning.
"Who was you with" is ungrammatical for most English speakers (since it corresponds to "You was with X").
The claim "prepositions in questions usually come at the end" is wrong without some further specification. If the preposition logically precedes the question word (who, which, what etc) then in colloquial English it usually goes to the end: that is, most people would say "Who did you go with?" rather than "With whom did you go". But this does not apply when the preposition goes with a noun phrase that is not the question term ("with you").
"With whom were you?" is correct, but unfamiliar to the native speaker's ear. You could also put the "with" at the end,"Who was the person you were with?" However, there is no need to do so and your original instinct is the best choice.
