seem是动词,词义为看起来像.因为know也是动词,所以很明显不能用He seems know a lot.
而因为seem to do 也是固定搭配,接动词不定式
同时还有一种同义句式,It seems to.
句意是：他看起来好像知道很多.这个句子的谓语是哪个？是seems to还是know?？