[Grammar] What ... for?

[Boris Tatarenko]

Hello everyone.

My learn book says: "You can use What ... for? to ask about purpose":

1. What is this switch for?
2. What did you do that for?

I'm not sure that I understood this rule correct. But I have some doubts:

Can I say: For what this switch? and What did you do for that? Does it sound unnatural and ungrammatically?

Thanks in advance.
Boris.

P.S
I have lost my account access (my past account was Nicklexoxo) Can somebody help me to re-establish it? Thanks.

 

[SoothingDave]

No, you can't re-arrange the structure.

 

[Rover_KE]

Stick to the structures of 1 and 2.

Your alternatives are both unnatural and ungrammatical.

Rover

 

[MikeNewYork]

Hello everyone.

My learn book says: "You can use What ... for? to ask about purpose":

1. What is this switch for?
2. What did you do that for?

I'm not sure that I understood this rule correct. But I have some doubts:

Can I say: For what this switch? and What did you do for that? Does it sound unnatural and ungrammatically?

Thanks in advance.
Boris.

P.S
I have lost my account access (my past account was Nicklexoxo) Can somebody help me to re-establish it? Thanks.

You can change #2 into "Why did you do that? But that will not work in #1.