Learn French: Vous entendez quoi ?

In everyday spoken French, it is very common to keep the normal statement word order (Subject + Verb) and just put the question word at the very end. This literally translates to "You hear what?".

Why do we use quoi for "what" instead of que?

Both que and quoi mean "what". However, when the question word is placed after the verb, you must always use quoi. You only use que if the "what" comes at the very beginning of the sentence.

I thought the verb for listening was écouter. Why use entendez?

They have different meanings! Écouter means "to listen" (doing it on purpose, like listening to music). Entendre means "to hear" (a sound simply reaching your ears). This sentence uses entendre because it asks what noises or sounds you are passively picking up.

Do I pronounce the "s" at the end of vous in this sentence?

Yes! Normally the "s" in vous is silent, but because the next word (entendez) starts with a vowel, the "s" wakes up and is pronounced like a "z" to link the words together smoothly. This is called a liaison, making the start of the sentence sound like "voo-zahn".