When should we shut our mouth?

There are 10 occasions that we should shut our mouth and say nothing to avoid trouble :

1) When we are angry - whatever we say is wrong
2) When we don't know - to guess , if we don't know, we should say we don't  know
3) When two brothers are arguing,  you as an outsider should stay out
4) When nobody needs your opinion, you should shut your gaps
5) When you know someone is telling a lie to get out of trouble. Your talking will bring more trouble.
6) When you saw someone is cheating on their better half, we should not confront them.
7) When what is say is going to kill a person, we should shut up
8) When someone is talking on a phone and you don't know what is he or she is talking about
9) Never talk about hearsay or rumours.
10) Never talk about personal defects or hygience of another person.

Namaste.