Sorry for the topic name, but I still don't know which version is correct.
What is the problem?
I tell you what the problem is. - I often hear this
I tell you what's the problem. - I often hear this
I tell you what is the problem. - I never hear this
Okay, my main question:
Are answer 1 and 2 correct?
Is answer 3 wrong?
I can't see how you think that the third is wrong while the second is correct. A single apostrophe makes it grammatically incorrect, don't you think that this is a bit strange?
The first one is correct in the sense I assume you meant.
But the second and the third may be correct especially, one mimics a question which has just been asked and found it silly or annoying or something like that.
Okay, maybe they said: "I'll tell you...".
However, I cannot guarantee this...
(It's not always easy to understand words when they are quickly spoken.)
I will tell you why.
This reminds me of this:
Can you not help me? - correct
Can't you help me? - correct
Cannot you help me? - wrong!
And that's why I thought it could be the same with the "What's" instead of "What is".
Okay, I guess these are two completely different cases, but well...
Hmm I guess
"I'll tell you what's good" and "He knows what's good" is right, because "is" and "good" are linked, aren't they?
Probably the same as "is going on".
I know what is going on - this is definitely right, I've learned this here
Not easy guys, not easy...