What If I Told You?

You may follow it by an optional "that," and any statement.

What if I told you [that] you just won a million dollars?
What if I told you [that] the stock market is about to crash?
What if I told you [that] you don't have any money left?

The statement may be negative or positive. It's usually able to stand alone as a declarative sentence.
But when you add it to your "question" phrase, the whole thing becomes an interrogative sentence.
That is, it's asking for a response, or an answer.

You can also substitute "Suppose I told you that etc." In this case it's not really a question, and you wouldn't use a question mark at the end. This one is an imperative sentence. But nevertheless, it invites a response.

Thanks.So it is not a conditional sentence.Is it?I thought writing like "What if I told you you don't have any money left?" was wrong.I thought it should be written as What if I told you you didn''t have any money left?..Anyway thanks again

Good question!
You can always backshift, but it's not necessary when you're talking about a currently existing condition.

Yes, it's conditional.

Consider a case of reported speech: Did I tell you that you don't have any money left?
You could backshift this: Did I tell you that you didn't have any money left? (We're talking about a present condition.)
Personally, I would not backshift this.

Opinions may vary.

Yeah,now I get it...Your reported speech example was great.

Yes, you are correct.Listener should have a good English knowledge to understand those backshifted sentences are about a present condition.In our country ,it is hard to find people who have that sort of grammar knowledge.

Now confusion is totally over.Thank you very much,

Another question..Can't we use "what if I tell you"..when we talk about the present condition?

VibhanuAnother question..Can't we use "what if I tell you"..when we talk about the present condition?

Yes, we can.

Thanks for the kind words. I'm afraid my native instincts are sometimes stronger than my knowledge of the formulas, especially where conditionals are involved.

Regards, - A.