I know that very well, 什么意思

I know that very well, 什么意思
I know that very well, 什么意思

I know that very well, 什么意思
I know that very well,
我非常了解那个（事,人,物都行）
I know （that）that is very well,
我知道那个非常好
你应该是这两句分的不清楚吧~