care 名词
He looked after her with care.
careful 形容词,用于修饰名词.
He is a careful boy.此处careful用于修饰boy.
carefully 副词,用于修饰动词.
He looked after her carefully.此处carefully用来修饰look after.
care除了有小心 还有喜爱 介意的意思.
剩下两个就都是小心的(地)的,仔细(地)的 的意思
用法：
1.be careful 小心点,让对方多加留意,谨慎小心
be careful with.../ be careful not to do sth
2.be carefully 不是固定搭配,后面还应该接动词的过去分词,表示"被小心/仔细地..."
如:This task should be carefully finished.