四級考試常用語法精選（4）

　　to do

　　完成式

　　to have been done

　　to be doing

　　完成進(jìn)行式

　　完成式: 不定式的一般形式所表示的動(dòng)作, 通常與主要謂語表示的動(dòng)作同時(shí)發(fā)生, 或是在它之后發(fā)生. 假如不定式所表示的動(dòng)作, 在謂語所表示的動(dòng)作之前發(fā)生, 就要用不定式的完成式.

　　I am glad to have seen your mother .

　　He is said to have written a new book about workers.

　　He pretended not to have seen me.

　　進(jìn)行式: 如果主要謂語表示的動(dòng)作發(fā)生時(shí), 不定式表示的動(dòng)作正在進(jìn)行, 這時(shí)要用不定式的進(jìn)行式.

　　You are not supposed to be working. You havent quite recovered yet.

　　We didnt expect you to be waiting for us here.

　　He pretended to be listening attentively.

　　完成進(jìn)行式: 在謂語所表示的時(shí)間之前一直進(jìn)行的動(dòng)作, 就要用不定式的完成進(jìn)行式.

　　The struggle was known to have been going for twenty years.

　　We are happy to have been working with you.