He should have been more careful.
He should pay attention and notice that.
Notwithstanding , he must be prosecuted.
You don't have to fuss over him.
You don't have to be so considerate with him.
It is necessary that he prepare for the worst.
Things turned out to his advantage.
I recommend caution in dealing with him.
You must make allowance for his inexperience.
I should have talked to him more.