小升初必備語(yǔ)法：不定式的時(shí)態(tài)和語(yǔ)態(tài)

　　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(shí)：一般現(xiàn)在時(shí)表示的動(dòng)詞，有時(shí)與謂語(yǔ)動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生，有時(shí)發(fā)生在謂語(yǔ)動(dòng)詞的動(dòng)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(jiàn)到你。

　　2) 完成時(shí)：表示的動(dòng)作發(fā)生在謂語(yǔ)動(dòng)詞表示的動(dòng)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(shí)： 表示動(dòng)作正在進(jìn)行，與謂語(yǔ)動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生。

　　He seems to be eating something.

　　4) 完成進(jìn)行時(shí)：

　　She is known to have been wreaking on the problem for many years.