be clear about 与be clear to的区别是什么?Are you clear with what I said? Is that clear to you?

be clear about ...：意思是“要清楚...”、“必须清楚...”,实际是否清楚还未确定,是将要发生的事情,是将来语态.
be clear to...：意思是“很清楚...”、“已经清楚...”,是已经确定的事实,是已经完成的事情,是完成语态.
Are you clear with what I said? Is that clear to you? 你清楚我说的话吗?你明白了吗?