干嘛呢

what are you doing?

→ 干嘛
phrase Uncommon #10,799
what are you doing? A casual question meaning “what are you doing?” or, depending on context, “why are you doing that?” The 呢 adds a questioning tone and often makes the question sound conversational.
CH: 你们在这儿干嘛呢?
EN: What are you doing here?

想那个干嘛呢?

Why bother thinking about that?

— 母亲 (2009)

小伙子,在这儿干嘛呢?

Hey, young man, what are you doing here?

在家干嘛呢?

What are you doing at home?

你们干嘛呢

What are you guys doing?

— 孤胆特工 (2010)

你在那干嘛呢

What are you doing over there?

— 满江红 (2023)

你们俩干嘛呢?

What are you two doing?

— 世界 (2004)

你俩干嘛呢?

What are you two doing?

— 世界 (2004)