Learn English – Have/Had met before

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.

For example:

Are you met before? You are met before.

-versus-

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.

-versus-

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].

Firstly, let's tackle the use of the phrase "you know everything there is to know about me" and ignore the word "else" for now.

It would be equally grammatically correct (and not really change the meaning, either), to say "you know everything about me." In this context "there is" is basically synonymous with "that exists."

You know everything [that exists] to know about me.

So, reworded, this means of all the things there are to know about me, you know every single one. This is obviously the same meaning as just saying you know everything about me. It is, however, a slightly more emphatic way of saying it. Generally the more words you use to express the same meaning the more emphatic you'll sound. So "you already know every tiny little thing there is to know about me" sounds even more emphasized (and, in this context, more aggressive, too).

So the other half of your confusion seemed to come from the word "else." "Else" needs to refer to something, and in the specific context of this sentence, ought to refer to the only thing the listener didn't already know (or still doesn't). It's easier to see why it's being used when the thing it's referring to is in the previous sentence.

I'll leave you instructions on how to prepare the side-dish, but you know everything else [about preparing this meal].

Here the "else" is all the meal preparation other than the side-dish.

Do you really not know my favorite color? How is that possible? You know everything else there is to know about me!

Here the "else" is everything about the speaker other their favorite color -- which brings us back to the context you provided.

Without knowing exactly how the conversation went prior to this sentence and only having the vague context it's a little hard to say exactly what the "else" is referring to. It sounds like she may have just asked him a question, such as "Would you like some sugar in your tea?" or perhaps "Why are you upset?" and he responded with this, meaning she already knows all facts about him other than this, and thereby implying she should probably also know whether he takes sugar or why he's upset. There is a little wiggle room here since he's obviously being sarcastic and refusing to come out and say what he actually thinks, so he may even be referring to everything other than the fact that he doesn't like horse racing.

Regardless of the words he picked, what he's actually saying is, "You are acting like you know more about me than you actually do, and I want you to realize that."