
You know better than to go off all alone.
"to know better (than to do sth) ""你知道不該去做sth"
eg: A: A stranger man was following me when I was walking home last night.昨晚我回家的時候有個陌生男人一直跟著我.
B: You should know better than to walk alone at night.你該知道別晚上一個人走.