Throwing a word back: X + gì mà + X

When someone uses a word you disagree with, you can throw it back: the word, then gì mà, then the word again. Mắc gì mà mắc! Expensive? It isn't expensive at all! (in Hà Nội, Đắt gì mà đắt!). The reason often follows: Mệt gì mà mệt, mới đi có chút xíu. Tired? We've barely walked.

It works with verbs too, usually to stop someone doing something: Ngủ gì mà ngủ, dậy đi học! Enough sleeping, get up for school!

The shorter form, the word and gì đâu, is softer. It's the modest way to answer a compliment: Em giỏi tiếng Việt quá! Dạ, giỏi gì đâu chị. Oh, not really. With people you respect, keep to this one; the full form can sound impatient.

Không mắc chút nào simply states a fact, and Đâu có mắc! denies what someone said. Mắc gì mà mắc! goes further: it throws back their very word.

… làm gì (what's the point of …) also talks someone out of something. Lo gì mà lo! and Lo làm gì! both mean "don't worry", but gì mà waves the worry away briskly, while làm gì gently asks what good it does.

When a different word follows mà, it's a complaint that asks why: Làm gì mà lâu vậy? What's taking you so long?