' All ' vs ' Any ' - Please clarify the usage

"Any" should be used only in negative sentences and questions. Therefore, the second sentence is incorrect

Kasia@MasterGMAT wrote:"Any" should be used only in negative sentences and questions. Therefore, the second sentence is incorrect

@Kasia
Well, I get the fact that usage of "any" in the mentioned question was wrong. But I am not able to understand what you imply by negative sentences and questions.

Here are few of the sentences that are coming to my mind (with any):
1) Can any of you help me with this question?
2) Any of the three guys sitting in those chairs can be a winner.
3) Any one who can answer this question will be given a suitable reward.
Please care to reply.

I was referring to the MOST BASIC use of "any."
e.g. Is there any milk?
There aren't any free seats available.
Your examples are of course correct. Note that each of them uses ONE structure "any(one) + can..."
Also your first example is a QUESTION, isn't it?

1) Can any of you help me with this question? -
2) Any of the three guys sitting in those chairs can be a winner. -
3) Any one who can answer this question will be given a suitable reward.

Thanks Kasia!
I thought you are saying the questions should also be negative. Bad inference