你可以说："I need to take care of him."
这句话的来源是英语中的动词"take care of"，意思是照顾，护理，照料。
例句：
"I have to take care of my pttle sister after school every day."（我每天放学后都要照顾我的妹妹。）
"Can you take care of the dog while I'm away?"（我不在时你能照顾一下狗吗？）
"She is responsible for taking care of the plants in the garden."（她负责照料花园里的植物。）