Unit 6 Grammar课件 2023-2024学年沪教牛津版英语八年级上册

Unit 6 Ancient Stories Grammar “for + 段时间”，意为“(到现在为止) 有……的时间了”，如 for a long time, for 10 years等等。 与现在完成时连用时需注意以下几点： 瞬间动词不能与“for+一段时间”连用表示动作的连续性，应改用持续性动词。如：He has left for five minutes. ( ) He has been away for five minutes. ( ) 瞬间动词表示短暂的动作，如come，go，leave，start, begin, become, receive, die等；而持续性动词表示能持续一段时间的动作，如work，stay，live，learn等。 瞬间动词的否定形式可以与“for + 一段时间”连用，说明某个动作不发生的状态已持续了一段时间。如：I haven’t met him for years. “since + 时间点”， 意为“自……以来”，如 since August 2003, since yesterday, since two o’clock等。 与现在完成时连用时需注意以下几点： 瞬间动词的否定形式与“since+时间点”连用表示某动作不发生的状态已经持续了一段时间。如： I have waited here for you since 2 o’clock. I haven’t heard from him since March. 此外，since后还可引导时间状语从句，且从句中的谓语动词通常用一般过去时。如：Helen has not been back to her primary school since she left. 注意：for和since不能同时使用。如： Alice has lived in Beijing for twenty years since 1993. 注意：瞬间动词不能直接和for 或since 连用，但我们可以找一个相应的延续性动词或表示状态的形容词、副词或介词短语来替换这些瞬间动词。转换后即可在现在完成时中与表示一段时间的状语连用。 少数瞬间动词可以转换为其相应的持续性动词，如： borrow → have/has kept buy → have/has had 有些瞬间动词可以用相应的介词短语、形容词、副词或名词与be的现在完成时连用，表示状态的延续，如：arrive in/at → have/has been in/at, join → have/has been in或have/has been a member of die → have/has been dead, leave → have/has been away, begin/start → have/has been on, end/finish → have /has been over come to → be in / at, go out → be out, open→ be open, close → be closed 瞬间动词（组）和持续性动词（组）转换示例 Choose since or for when they are in the present perfect tense _______ 1997 _______ a long time _______I was 12 _______ two days ago _______ a month _______ he was born _______ ten years since与for划线提问都用how long, 用法相同 for for for since since since since 选用since或for填空。 1. ______ two years 2. ______ two years ago 3. ______ last month 4. ______ 1999 5. ______ 4 hours 6. ______ an hour ago 7. ______ we were children 8. ______ she left here for since since since for since since since I. 根据句意，用 since 或 for 填空。 1. The man has stayed here _______4 pm yesterday. 2. D