Learn French: Vous avez soif ? Je vous en verse un verre. - Are you thirsty? I am pouring you a glass of it.

When combining an indirect object pronoun like vous (to you) with the pronoun en (of it/some), the indirect object always comes first. The pronoun en (just like y) is always placed right before the verb, coming after all other object pronouns.

What exactly does en stand for here?

The pronoun en replaces a noun phrase introduced by de (of). Even though the specific drink isn't named in the first sentence, en replaces something like de l'eau (some water). So Je vous en verse un verre literally means "I pour you a glass of it."

Why is the quantity un verre left at the end of the sentence?

When using en with a specific quantity (like a number or a measurement), en replaces the item itself, but you must keep the quantity word at the end of the clause. For example, Je verse un verre d'eau (I pour a glass of water) becomes J'en verse un verre (I pour a glass of it).

Why does the first sentence use avez (have) instead of the verb for "are"?