思考動詞と認識動詞

�a. It seems (that) I have caught a cold.
b. I seem to have caught a cold.
�a. It seems (that) he was late for the train.
b. He seems to have been late for the train.�a.It seems (that) they will leave the city.
b.They seem to leave the city.

これらの文はitの置き換えが見られるが、itは文主語であって、普通の思考動詞の場合のように目的語のitではない。

a→ただの思考内容の表現
b→ある具体的な主題についての陳述

☆意味のニュアンスが違っている。