"What are you doing?"

Translation: 你在做什么？

[Jenna_Elise]

Why is the 在 there?

[Keith_APP]

It means "in the course of". It is used for a continuous action.

[samertabbal]

Implies -ing (continuous action)

[akavel]

I think it is like "present continuous tense", corresponds to the "-ing"

[orgat]

你做什么 (without 在) is idiomatic and should be accepted.

[AlexisRuss19]

I get that 在 is in there to imply continuous action, but does "你做什么?" convey the same meaning?

[PeaceJoyPancakes]

"你做什么" is accepted now, and can be "what do you do" or "what are you doing", depending on context, whereas "你在做什么" is clearly progressive.

[JacynDaniels]

yes thats what I thought as well

[fhwqhgads]

I know this is a year late, but if anyone else comes across this thread, "你做什么？" means "What do you do?" Very different from "What are you doing?" Although a Chinese speaker would not interpret "What do you do?" to mean "What is your job?" they would still understand it very literally.

The real alternative is “你在干什么？“ The new character is "gan4"

[LaBiciEsMia]

How about "你(在)干什么" ?

[PeaceJoyPancakes]

Also okay.

[deactivated user]

你在做怎么? nǐ zài zuò zěn me Vs. 你在做什么? nǐ zài zuò shénme - What's the difference?

[Keith_APP]

你在做怎么? is not a correct sentence.
怎么 is how.
The sentence is therefore saying You are doing how?.
If you want to say how you do?,
(which also translates to English as What do you do?)
the word order is
你怎么做?

[konstantin.05]

“你在干嘛”怎么不对啊？

[PeaceJoyPancakes]

Also okay.

[RixMorales]

Why is 你在什么做？wrong? But there are other instances where the question is in this order 什么做

[PeaceJoyPancakes]

Perhaps you're thinking of "怎么做", "how to do it".

"你是什麼做的" is "what are you made of", i.e. what's your chemical composition etc.

[HasnainSikandar]

why cannot be 你在 看 什 么书？

[HasnainSikandar]

why cannot be 你在 什 么做?

[YureiKertia]

It's because 做 is a verb, meanwhile 书 is a noun. A noun is placed after 什么，a verb befor it. Literally translated you ask "You are doing what?" but ask "You like reading what books?"

(I'm not a native or anything so take this amswer with a pinch of salt)