1) 一般式表示的動(dòng)詞,有時(shí)與謂語動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生,有時(shí)發(fā)生在謂語動(dòng)詞的動(dòng)作之后,例如
He seems to know this. 他似乎知道這事。
I hope to see you again. = I hope that I’ll see you again.我希望再見到你。
2) 完成式表示的動(dòng)作發(fā)生在謂語動(dòng)詞表示的動(dòng)作之前。例如:
I’m sorry to have given you so much trouble. 很抱歉,給你添了那么多的麻煩。
He seems to have caught a cold. 他好像已經(jīng)得了感冒。
3) 進(jìn)行式表示動(dòng)作正在進(jìn)行,與謂語動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生。例如:
He seems to be eating something. 他好像正在吃什么東西。
4) 完成進(jìn)行式表示動(dòng)作從過去開始并延續(xù)至說話的時(shí)候。例如:
She is known to have been working on the problem for many years. 我們知道她研究這問題有好幾年了。