Please tell me why this phrase is incorrect

Question

I encountered this phrase while reading a local paper:

What club does your friend a part of?

For some reason, I know that this phrase is incorrect.

I used two grammar checker websites, such as QuillBot, and Writer, to check whether my suspicion was valid, and I was right. Both websites corrected the phrase to these:

QuillBot

What club is your friend a member of?

Writer

What club is your friend a part of?

I also used Ludwig to search for phrases that has similar construction but to no avail.

Personally, I think

Which club is your friend a member of?

and

What club does your friend belong to?

are correct. But I can't explain why

What club does your friend a part of?

is incorrect. Can you please tell me the grammar rules behind this?

Answer 1

The main difference between the multiple results your grammar checkers have churned out is the correcting of the verb 'does' to 'is'.

A dictionary will tell you that these are entirely different verbs - forms of to do, and to be respectively.

Being a member is something a person is. If you were a member of a club you could say "I am a member" at any time, whether you were at the club or not.

By sharp contrast, to do something denotes an action or an event. You can't say you are doing something when you are not. One does not 'do' a membership, and that is why your original sentence is wrong. You could ask "which club does your friend go to?", because 'go' is another verb denoting an action which is done.

The difference between 'what' and 'which' is more dependent on the context. We use 'which' when presenting a limited choice. For example, after talking about 2 different clubs, you might ask which (of the two) is a person a member of. 'What' is more open-ended.