I know better than to mention it.
我才不会提它呢.
You ougut to know better than to tire yourself so.
你应该懂得把自己累成这样是不对的．
I know better than to lend him any money.
我知道不该把钱借给他.
You ought to know better than to go swimming after a big meal.
你应该知道吃饱了饭最好不要去游泳.