Is this a correct sentence?

tenjing I couldn't have told her the truth that her brother was lying on a road yesterday because he was there with her.

It's grammatically correct, but it's puzzling what situation it's trying to describe. Someone lying on a road? Was he trying to commit suicide?

I mean to say the guy was drunk and lying on a road.

I was afraid to her about it in front of him. The use of 'couldn't have' is correct in the above sentence with the situation, right? ?

I was afraid to tell her, I missed 'here's.

tenjing I was afraid to tell her about it in front of him. The use of 'couldn't have' is correct in the above sentence with the situation, right? ?

I'm having trouble following what you are asking. Can you write out the whole situation? Something like this:

Her boyfriend was lying drunk on the road. I wa

Jim was drunk and lying on a road yesterday and I saw this. When I went to Jim's house to tell his father that I saw him lying on a road yesterday and he was drunk, but Jim was there, so I didn't tell his father cause Jim is my friend and I didn't want Jim to get angry with me for telling about it to his father.
Now my another friend, Alex, asks me,"why didn't you tell Jim's father about h

tenjingIs the use of 'could've' correct?

Actually, it's "couldn't have", but yes, it's correct.

CJ

I would say "I couldn't tell his father".