内容正文:
Unit8 Safe and sound
⭐Grammar知识点清单
第一部分 Grammar:过去进行时 Past continuous tense
一、核心定义与结构
1. 用法:描述过去某个具体时刻正在发生的动作;长动作背景下发生短暂突发动作。
2. 构成公式:was /were + 动词 - ing
· 单数主语 (I/he/she/it/ 单数名词) → was doing
· 复数主语 (we/you/they/ 复数名词) → were doing
3. 时间连词:when /while/as 均表示 “在…… 期间”
二、when /while/as 完整区分规则(考试核心考点)
1. while
后面只能接延续性长动作(过去进行时),主从句均为长动作优先用 while。
People were running while bricks were raining down.
2. when
后可接短暂动作(一般过去时),也可接长动作;主句是长动作、从句突发短动作用 when。
I was working when the earthquake started.
3. as
侧重同步伴随,“一边…… 一边”,多用于书面叙事。
As I was trying to find my way out, I heard a noise.
三、两种时态搭配逻辑(长动作 = 过去进行;短突发 = 一般过去时)
1. 主句长动作 (was/were doing) + when + 从句短动作 (一般过去时)
Millie was watching TV when lightning hit the building.
2. 从句长动作 (was/were doing) + when/while/as + 主句短动作
While Millie was watching TV, lightning hit the building.
3. 主从句都是同步长动作,统一用 while 连接
We were watching while firemen were putting out the fire.
四、A、B 习题时态判断思路
1. 明确过去具体时间点(at 7 this morning /when I got up),持续动作用过去进行时;瞬间发生动作用一般过去时。
2. 例句:
It was getting stronger while I was reading.(两个同步长动作)
It was snowing when we went to the museum.(背景长动作 + 出行短动作)
I drew a big smile…(瞬间完成,一般过去时)
第二部分 Word power:复合词 compound words
一、四大复合词构词规则(名词 + 名词 / 动词 / 形容词组合)
1. 名词 + 名词 名词 + 名词
thunderstorm 雷雨;snowball 雪球;teamwork 协作
2. 名词 + 动词 名词 + 动词
earthquake 地震;waterfall 瀑布;sunrise 日出
3. 动词 + 名词 动词 + 名词
playground 操场;driveway 车道;passport 护照
4. 形容词 + 名词 形容词 + 名词
whiteboard 白板;software 软件;gentleman 绅士
二、课本高频复合词分类
1. 职业类:policeman, policewoman, postman
2. 病痛类:headache 头痛;toothache 牙痛
3. 出行地点:airport 机场;postcard 明信片
4. 基础合成词:countryside, weekend, something, everything, endpoint
三、A 配对变形核心
1. police + man → policeman;police + woman → policewoman
2. head + ache → headache;tooth + ache → toothache
3. post + man → postman;post + card → postcard
4. air + port → airport;pass + port → passport
四、B 短文填空复合词(词框合成)
country + side → countryside 乡下;week + end → weekend 周末
post + man → postman 邮递员;some + thing → something 某物
三、两大板块综合语法易错汇总
过去进行时易错点
1. 时间点必须是过去特定时刻,泛指过去不用过去进行时。
2. while 从句不能接短暂动词 (hit/start/fall),只能用 when。
3. 双写、去 e 变 - ing:run-running;write-writing;blow-blowing
4. 瞬间动词(draw/stop/arrive/hit)只用一般过去时,不用进行时。
复合词易错点
1. 复合名词复数只变后一词:policeman → policemen;postman → postmen
2. headache/toothache 固定搭配,不可拆分
3. countryside 乡下,不可写成 contryside
4. something/anything 不定复合代词,形容词后置 something burning
四、易混词辨析
1. when / while
while 只接延续进行时;when 长短动作均可
2. past continuous / simple past
过去进行:过去时段持续画面;一般过去:过去瞬间完成动作
3. passport / airport
passport 护照(pass+port);airport 机场(air+port)
4. weekend / countryside
weekend 周末;countryside 乡村郊外
五、灾害作文万能句型(融合两大考点)
过去进行时句型
1. I was walking home when a heavy snowstorm came suddenly.
2. While the wind was blowing hard, people were clearing snow in the street.
复合词融入句子
1. The policeman told us to stay away from the broken buildings after the earthquake.
2. I found something burning in the kitchen and put out the fire quickly.
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