- Have you met her before
- Are/were you met her before
Which one is correct? If both are correct then in which situations should they be used?
Although are/were are used to form questions, they don't work with met. It should be have you met [her] before? (If these two people are both present, her is not necessary; you only need it if you're talking about someone who's not there at the time).
In questions that use subject auxiliary inversion (e.g. when You are ... becomes Are you ...?), and that don't use interrogatives (e.g. who/what/where/etc.), there is an easy way to tell whether or not you're using the correct auxiliary: simply rearrange the sentence to see if it makes sense as a statement.
Are you met before? You are met before.
Have you met before? You have met before.
The second is the only one that makes sense. That's the easiest way to figure it out.
You do have one other option here; you could use do as the auxiliary. But in this case, it can't be used with met. You'd have to switch the verb to know for that to work. And it would need to be in the present tense. The rule that I've mentioned above still applies:
Do you met her? You do met her.
Do you know her? You do know her.
You'll know to use know because it agrees with do in tense (i.e. both simple present).
Most often, these types of questions use have, had, or do.
Questions involving forms of to be (e.g. are/were), are generally about states of being/existential, mood/feelings/emotional states, location, and actions about to occur: (e.g. Are we going to leave now?, Are you there?, Are you mad?, Were they at the party?, etc.).
Depending on the context and temporal factors, you might be able to use did. This would make the main verb present tense though. If this is after the fact, you could instead say:
Did you meet her? You did meet her.
Did you know her [back then]? You did know her [back then].
When I want to ask someone if they know another someone, I usually use either "Have you met her before?", or "Do you know her?"
Using "Are/were you met her before?" will make it look like a passive voice, but, it is not grammatically correct. At least it will need by, then it might make some sense. But then again, I've never heard anyone said "Are/were you met by her before?" before. So I say, don't use it.
The more common usage is, "have you met her before." This is a past participle construction.
The other usage, are you met her? is a "state" construction that is archaic. President Abraham Lincoln used it in his Gettysburg Address (1863): "We are met on a great battlefield of that [Civil] war." But it has seen little use since then.
The sentence fragment
Were you met
is not ungrammatical, but it begins a passive construction which has to be completed properly with a phrase which specifies the agent: to be met (by someone or something, or with something) is the passive version of meet.
The proposal to build an oil pipeline was met with opposition.
Stepping out of the limousine, Justin Timberlake was met by a throng of squealing female fans.
Were you met her before
is ungrammatical, because the passive "you were meet" requires a prepositional phrase based on "by":
Were you met by her before.
English speakers are very unlikely to use this sentence, even though it may be grammatical. The reason is that the above sentence is the passive form of this one:
Did she meet you before?
The third person being discussed (she) is the agent of the action ("to meet") and the person we are speaking to is the object. This is an unusual point of view to take.
When we speak to someone about meeting some third person, we take the point of view of the person we are speaking to as being the agent of the meeting, and that third person as being the object. Simply:
Did you meet her before?
Reversing the point of view for this verb is quite awkward, and then turning it into a passive sentence just makes it more awkward.