seen和seem是什么意思 他们都有什么固定搭配? 像seen to do这样的

seen是see 的过去分词。see sb。do sth。看见某人做某事。（动作结束或习惯动作）We see her sing songs every daysee sb。doing sth。看见某人正在做某事。We see her singing songs nowseem。1）系动词seem+形容词。He seems happy2)。不及物动词 seem to do sth。或It seems that 从句He seems to know everythngIt seems that he is happy