[Grammar] What are you doing that for?

[sky3120]

1) What are you doing that for?

2) For what are you doing that?

3) Why are you doing that?

I have learned that what for means the same as why and then how about for what? I think that all of them mean the same, but I am not sure. What do you native English speakers think?

Thank you and have a good day.

 

[Rover_KE]

I have learned that what for means the same as why and then how about for what?

Yes, 'what for' means 'why', and 'why' means 'for what reason', so #2 should be 'For what reason are you doing that?'

 

[sky3120]

Thank you so much, but I can hear 'for what' a lot in movies and here and there, and then, what is the meaning of 'for what'?

 

[charliedeut]

I'd say "for what" may be acceptable in oral, non-standard English (which is sometimes portrayed in movies).