内容正文:
2023外研社九年级英语上期末复习专项—核心语法(二)
if引导的条件状语从句
【归纳】if引导的条件状语从句可放在主句前,用逗号把主从句隔开;主句在前从句在后,不用都逗号隔开;
※以下if引导的条件状语从句需用一般现在时表将来:
1. 主句有will/shall/won’t等;
【例句】If it snows tomorrow we won’t go to the park.
2. 主句有may/can/must等情态动词;
【例句】You can realize your dream if you work hard.
3. 主句是祈使句;
【例句】Please help me with my English if you are free.
被动语态(1)
1. 一般现在时的被动语态
【含义】表示现阶段经常性,习惯性的被动动作
【结构】肯定句:主语+am/is/are+及物动词的过去分词+(by+动作执行者).
否定句:主语+ am/is/are not+及物动词的过去分词+(by+动作执行者).
疑问句:Am/Is/Are+主语+及物动词的过去分词+(by+动作执行者)?
【例句】 主动语态:Students grow trees in spring.
被动语态:Trees are grown by students in Spring.
2. 主动语态变被动语态的步骤
步骤一:原主动句的宾语→被动句的主语;
步骤二:原谓语动词→“be+过去分词”;{注意}谓语动词的人称和数随着主语而变,be动词时态不变,不论什么时态,被动语态的句子必须有一个be动词.
步骤三:原主动语态的主语,若强调就放by后,以宾格形式出现,以此来发出该动作的人/物;若无必要,就省略;
步骤四:其他成分(定语/状语)不变。
主动句 主语+及物动词+宾语
被动句 主语+be+及物动词过去分词+by+宾语
【例句】lots of people around the world learn Chinese. → Chinese is learnt by lots of people around the world.
被动语态(2)
1. 一般过去时的被动语态
【结构】肯定句:主语+was/were+动词的过去分词+(by+动作执行者).
否定句:主语+wasn’t/weren’t+动词的过去分词+(by+动作执行者).
疑问句:Was/Were+主语+动词的过去分词+(by+动作执行者)?
【例句】The house was built in 1998.
The house wasn’t built in 1998.
Was the house built in 1998?
2. 含复合宾语的主动句变被动句
(1) 原主动句宾语→被动句主语,原宾语补足语位置不变;
【例句】They call her Alice. → She is called Alice (by them).
(2) 一些感官动词/使役动词,其后宾语是动词不定式时,主动语态需用无to的动词不定式,变被动时,要带to;此类动词有:see/listen/let/have等;
【例句】I always see her dance in her room. →She is always seen to dance in her room.
被动语态(3)
1. 一般将来时的被动语态
【结构】肯定句:主语+will+be+动词过去分词++(by+动作执行者).
否定句:主语+will+be not+动词过去分词+(by+动作执行者).
一般疑问句:Will+主语+be+动词过去分词+(by+动作执行者)?
特殊疑问句:特殊疑问词+will+主语+be+动词过去分词?
【例句】This book will be written by Mrs. Smart.
This book will not (=won’t) be written by Mrs. Smart.
Will this book be written by Mrs. Smart? Yes, it will. / No, it won’t.
Whom will this book be written by?
2. 一般将来时被动语态的其他结构
(1) 主语+be going to be+动词过去分词.
【例句】The problem is going t