My friend invited us to play basketball at his gym. I say: I'd come if I were there

[B45]

My friend invited us to play basketball at his gym. I say:

I'd come if I were there.

VS

I'd come if I was there.

And

I'd go if I were there.

VS

I'd go if I was there.

Are all four okay?

 

[Roman55]

I am not a teacher.

None of these make sense to me.

If I understand you correctly, you have been invited to play basketball but you haven't gone yet. It is something that (if it happens at all) will take place in the future.

I would use "I'll" in this situation, making the appropriate changes to the rest of the sentences of course.
'I'll come if I can'.
'I'll come if I'm in town'.

"I'd" would be suitable if you already know that you aren't coming (or going) and want to explain why not.
'I'd love to, but I'll be out of town'.
'I'd come if I enjoyed basketball, but I don't so you won't be seeing me there'.

 

[B45]

Oh right, sorry, but I should've clarified that we're in different countries and he sent out a group chat via a mobile software.

My friend invited us to play basketball at his gym. I say:

I'd come if I were there.

VS

I'd come if I was there.

And

I'd go if I were there.

VS

I'd go if I was there.

 

[bhaisahab]

"I'd come if I were there."

 

[MikeNewYork]

I prefer "I'll come if I am there."

 

[bhaisahab]

I prefer "I'll come if I am there."

According to the OP he won't be there, Mike. They are in different countries.

 

[Tdol]

I'd come if I were there.

VS

I'd come if I was there.

And

I'd go if I were there.

VS

I'd go if I was there.

You will hear many native speakers use if I was there. However, were is the standard form and suitable for all occasions and contexts, while was would be considered inappropriate in formal contexts. Use were. You can use go/come.

 

[Raymott]

But wouldn't he know that, if you were there, you had come?
"I'd come if I were in X" would make more sense - (where X is where the basketball game is to be held.).

 

[MikeNewYork]

Being in different countries does not preclude travel. If he is is not here, he will not come.

 

[emsr2d2]

If you definitely don't plan to go, you can say "Unfortunately, I can't come. I would come if I were going to be in the same country [as you] at the time".