作者：沈建林
被動語態中的"省、補、變、加、留"指學習被動語態時應注意的"省主語、補主語、變代詞、加上to、保留by"這些關鍵內容。
"省主語"，指主動語態變被動語態時，如果主動句中的主語為泛指情況的we, they, people時，被動句中將by短語省略。如：
We speak English. →English is spoken.
"補主語"，指將字面未出現行為者的被動句改為主動句時，應適當地補上主語，如we, they, people, someone等。如：
A car is stolen. →Someone steals a car.
"變代詞"，指主動句中的賓語是賓格人稱代詞時，改為被動句要將其變為主格人稱代詞。如：
We must send her to the hospital at once. →She must be sent to the hospital at once.
"加上to"，如果主動句中含不帶to的不定式（作賓語的補足語），變該句為被動句時，不定式前的"to"應恢復使用。如：
We saw him leave the classroom. →He was seen to leave the classroom.
"保留by"，指下列被動句中by短語不省略的情況：
a. 當by短語不表示行為者，而表示使用的手段和方法時。如：
Most of the work will be done by the computers.
b. 強調by短語中的動作行為者時。如：
Macao was forced by Portuguese more than four hundred years ago.
特別提示：一般將來時的被動語態：shall / will be +p. p.
現在完成時的被動語態：have / has been + p. p.
現在進行時的被動語態：am / is / are + being + p. p.
過去將來時的被動語態：should / would be + p. p.
另外需特別注意的是英語中look, smell, feel, taste, sound等系動詞和表示"起止"意義的動詞begin, start, finish, stop等，主動形式可表被動意義。
考題回放：
1. -Did you go to Jack's birthday party?
-No, I______. (2004天津市)
A. am not invited B. wasn't invited
C. haven't invited D. didn't invite
2. I like this silk dress, and it ______ so soft and comfortable. (2004江西省)
A. is feeling B. feels C. has felt D. is felt
3. People use computers widely in the world. (改為同義句)
Computers ______ widely ______ in the world. (2002遼寧省)
4. 第四十七屆世乒賽上個月在巴黎舉行。中國乒乓球運動員贏得理所當然。
The 47th World Table Tennis Championship ______ ______ in Paris last month. The Chinese ping-pong players ______ ______ ______. (2003濟南市)
5. We heard them sing Peking Opera in that theatre last Sunday. (改為被動語態)
They were heard______Peking Opera in that theatre last Sunday. (2004重慶市)