時態(tài)\語態(tài) 主動 被動
一般式 to do to be done
進(jìn)行式 to be doing
完成式 to have done to have been done
完成進(jìn)行式 to have been doing
1) 現(xiàn)在時：一般現(xiàn)在時表示的動詞，有時與謂語動詞表示的動作同時發(fā)生，有時發(fā)生在謂語動詞的動作之后。
He seems to know this.
I hope to see you again. = I hope that I'll see you again. 我希望再見到你。
2) 完成時：表示的動作發(fā)生在謂語動詞表示的動作之前。
I'm sorry to have given you so much trouble.
He seems to have caught a cold.
3) 進(jìn)行時： 表示動作正在進(jìn)行，與謂語動詞表示的動作同時發(fā)生。
He seems to be eating something.
4) 完成進(jìn)行時：
She is known to have been wreaking on the problem for many years.