English Slang Collection：

　　go soft

　　[释] to lose strength or determination;

　　[例] The night before we went on our trip to Brazil, Mike went soft, which pissed the rest of the group.;

　　go south

　　[释] to turn worse;

　　[例] Pete's career went south after being busted for false account.

　　gotcha

　　[释] to show that you understand sb's words;

　　[例] A: If you don't wanna miss the flight, I suggest you to start loading the luggage. B: Gotcha!;

　　Gotcha

　　[释] I've got you;

　　[例] "Gotcha,you little thief! " the shopkeeper cried and called the cops.

　　go the extra mile

　　[释] to make a special extra effort in order to achieve something;

　　[例] You have go the extra mile to win their trust back.;

　　go the knuckle

　　[释] to have a fight or punch-up;

　　[例] If you ever do that again, I'll have to go the knuckle.