Expecting yes: … chứ?

Put chứ at the end of a statement when you're fairly sure the answer is yes and just want it confirmed: Mai em đi chứ? You're coming tomorrow, right? It sounds warm and a little insistent, like "…, of course?" or "…, I hope?"

It's often used to check on someone or on a plan: Anh vẫn khỏe chứ? You're keeping well, I hope? Em ăn cay được chứ? You can eat spicy food, can't you? In Saigon it's often said chớ.

The answer usually repeats the verb, often with chứ again: Dạ, đi chứ. Of course I'm coming. If the answer is no, say it gently: Dạ, chắc em không đi được. I'm afraid I can't make it.

Compare the other checking words. Có … không asks openly, with no guess. Phải không checks a guess calmly. Hả and à react to something you've just heard. Chứ assumes yes, so don't use it when you really don't know: it can sound as if you're pushing.

As an answer on its own, Có chứ! means "Of course!"

Inside a sentence, chứ không means "and not, rather than", with no question at all: Em uống trà chứ không uống cà phê. I drink tea, not coffee.