"What is this?"

Translation: 这是什么？

[Arash.....]

Why not "这个是谁?"?

[Sikeryali]

这 = This

个 = Qualifier

是 = is

谁 = Who?

[Arash.....]

Thanks

[mkmichael2]

This is what? ;-)

[DanielTBee]

Wouldn't 这什么 ，be okay?

[RanzoG]

I am also curious about this. It seems to me so far that 是 is not very often needed (e.g. as compared to how often its equivalent, "is" is needed in English. So I'd like to narrow down when 是 can be omitted.

[AMBMBF]

Does 这个什么 works??

[ahHk20]

I wrote 个 after 这，n Duolingo marked as a wrong. Why it's not correct here?

[Haruki_2000]

As far as I know, you need to follow by a noun after a counter like 个. The form is number + counter + noun.

[GavinRees5]

这个是什么 worked for me.

[Joops8089]

什麼東西？Is a phrase I heard used a lot in Taiwan to mean the same thing.

[womeiyoumingzi]

这是哪个 would be wrong?