"Two wrongs don't make a right."
When someone has done something bad to you, trying to get revenge will only make things worse.
"The pen is mightier than the sword."
Trying to convince people with ideas and words is more effective than trying to force people to do what you want.
"When in Rome, do as the Romans."
Act the way that the people around you are acting. This phrase might come in handy when you're traveling abroad notice that people do things differently than you're used to.
"The squeaky wheel gets the grease."
You can get better service if you complain about something. If you wait patiently, no one's going to help you.
"When the going gets tough, the tough get going."
Strong people don't give up when they come across challenges. They just work harder.
Source : http://www.phrasemix.com/