How to identify a complain or a "ask-for-help"?

How to tell if it is a complain,a "ask-for-help" or a question? Sometimes when a friend tells you something, you may mistakenly think it is a "ask-for-help" but in deed it is a complain, a catharsis. If it is a complain,all you should do is to listen to her/him and resist the urge/temptation to provide your advice.How to tell the difference between both? In my opinion, if this "ask-for-help" is unsolvable, or has no solution, then it is a complain; If you think the speaker can absolutely figure out the solutions on his own, then it is a complain. Do you think my methods to identify a complain or a "ask-for-help" are correct? Is there other better way to identify a complain or a "ask-for-help"?