My friend asks me if I liked her youtube video. I say to her to her: I'll let you

[B45]

My friend asks me if I like her youtube video.

I say to her to her:

I'll let you know after I watch the video.

VS

I'll let you know after I've watched the video.

Are both okay here?

 

[emsr2d2]

Yes.

 

[B45]

do they mean the same thing? Which would you say?

 

[Rover_KE]

FRIEND: 'Do you like my video?'

ME: 'I'll let you know when I've watched it.'

 

[emsr2d2]

Do they mean the same thing? Which would you say?

They mean the same thing. I would probably say "I'll let you know after I watch it".

 

[Polyester]

emsr2d2,
I'll let you know after I watched it.

Is it correct?

 

[MikeNewYork]

Some people would say that. I think the present perfect is better.

 

[Raymott]

I'll let you know after I watched it.

This is not correct in AusE, and I suspect BrE.
You could use that in the past: "I did let you know after I watched it yesterday."