Since when is he your friend? Correct it, please

[twilit1988]

Hi,

1) Since when is he your friend? Correct it, please

2) Please put this printer back to its place. correct it please

Thanks in advance for correcting sentences!

 

[bhaisahab]

Hi,

1) Since when is he your friend? Correct it, please

2) Please put this printer back to its place. correct it please

Thanks in advance for correcting sentences!

1) Since when is he your friend? This is OK, colloquial but OK.
2) Please put this printer back in its place.

 

[2006]

Hi,

1) Since when is he your friend? This sentence is often used to express doubt that "he" really is your friend.


son: I'm going to the mall with my friend Joe.

mother: Since when is he your friend!

2006

 

[Rover_KE]

Since when has he been your friend?

 

[Raymott]

Since when has he been your friend?

Yes, but I think the point is that that phrase is normally used ironically, (as above) rather than literally, as in "How long have you been friends with him?"

 

[JMurray]

1) Since when is he your friend?

I hope the previous respondents don't mind if I try and clarify this for Twilit.
The phrase as you've written it is, as others have mentioned above, perfectly good colloquial English but it has a very particular meaning. It is really saying, "I'm not sure he is truly your friend". It is skeptical.
However, if you are just asking for basic information about how long he has been a friend then you would say something like, "How long has he been your friend?", or "When did he become your friend?".