As the saying goes ( 所謂，俗語說...),idioms（成語,格言),elebration(詳解）。。。。
1.As the saying goes, predictions are hard to get right, especially when they're about the future。
2.As the saying goes, those who know aren't talking, and those talking don't know. But there are lots of exceptions.
3.As the saying goes,‘Those that ignore history are doomed to repeat it.’....
或者，
直接加在句子裏。
1。bark up the wrong tree
MEANING: choose the wrong course of action
He has been acting like an ape ever since his girlfriend left him.
2。Her bark is worse than her bite
MEANING: someone’s words are worse than their action
You shouldn’t worry about her. Her bark is worse than her bite and she is really a very nice person.