because是从属连词

because是从属连词，接表示直接原因的从句，一般放在主句的后面，也可放在主句前面，它表示的语气最强，在回答why的问句时，必须用because。

例如：The swimming pool won't be open today because they're making repairs.

游泳池今天不开放，因为他们在修理。

Why did you move to France?

你们为什么搬到法国？

Because my father found work in Paris.

因为我父亲在巴黎找到了工作。

注意：在英语中用了because后，不可再用so。

since 意为"既然"，表示对方已知的无需加以说明的原因或事实，语气比because弱，但是比as 强。

例如：Since we have no money, we can't buy that vase.

既然我们没钱，我们就不能买那花瓶。

Since everybody is here, let's begin our party.

既然大家都到了，那就开始我们的聚会吧！

because是从属连词，接表示直接原因的从句，一般放在主句的后面，也可放在主句前面，它表示的语气最强，在回答why的问句时，必须用because。

例如：The swimming pool won't be open today because they're making repairs.

游泳池今天不开放，因为他们在修理。

Why did you move to France?

你们为什么搬

4．过去分词由原形去字母e后，再双写后面的辅音字母加-en构成（＊例外）

hide-hid-hidden ride-rode-ridden write-wrote-written forg et-forgot-forgotten＊

5．过去分词由过去式加-n构成

break-broke-broken choose-chose-chosen freeze-froze-frozen speak-spoke-spoken steal-stole-stolen

6．完全不规则形式

am /

is-was-been are-were-been fly-flew-flown lie-lay-lain wear-wore-worn

二．过去式与过去分词形式相同

bring-brought-brought build-built-built buy-bought-bought

catch-caught-caught

dig-dug-dug feel-felt-felt find-found-found

get-got-got

have /

has-had-had hold-held-held keep-kept-kept leave-left-left lay-laid-laid lend-lent-lent lose-lost-lost pay-pa id-paid

hear-heard -heard make-made-made mean-meant-meant me et-met-met

say-said-said sell-sold-sold send-sent-sent sit-sat -sat

sleep-slept-slept smell-smelt-smelt spend-spent-spent spill -spilt-spilt

spit-spat-spat spoil-spoilt-spoilt stand-stood-stood swe ep-swept-swept

teach-taught-taught tell-told-told think-thought-thought win -won-won

understand-understood-understood wake-woke / waked-woken / waked

shine-shone / shined-shone / shined hang-hung / hanged-hung / hanged

learn-learnt / learned-learnt / learned

三．原形、过去式与过去分词三种形式完全相同

cost-cost-cost cut-cut-cut hit-hit-hit hurt-hu rt-hurt

let-let-let put-put-put set-set-set shu t-shut-shut

read /ri:d/-read /red/-read /red/

四．i-a-u变化形式

begin-began-begun drink-drank-drunk ring-rang-rung sin g-sang-sung

sink-sank-sunk swim-swam-swum

五．过去分词与原形相同

come-came-come run-ran-run become-became-become

六．情态动词（没有过去分词形式）

can-could must-must will-would may-might

shall-should

1 AAA型（动词原形、过去式、过去分词同形）

bet cast cost cut hit打 hurt伤害） let让 put放置

read（读）read read rid免除set安置

spread (伸展/传播) spread spread

quit放弃quit/quitted，quit / quitted

spit吐出spat / spit, spat / spit

wet淋湿wet / wetted ,wet / wetted

2 AAB型（动词原形与过去式同形）

beat（跳动）beat beaten

(3) ABA型（动词原形与过去分词同形）

become（变成）became become come（来）came come

run（跑）ran run

(4) ABB型（过去式与过去分词同形）

bend使弯曲bent，bent