but / while / however / though 意为“表“转折””

1. but 意为“但是；不过”， 着重强调前后的转折关系，并且转折的语气最为强烈。

2. while 意为“然而；但是”， 着重强调前后两者对比关系。

3. however 意为“然而；不过”， 表示意思的转折，常作插入语，并用逗号与句子隔开。

4. though 意为“尽管；然而”， 作副词时，位于句末或句中(位于句未时常用逗号隔开)；做连词时，引导让步状语从句。

全部

1·She fell while toddling around.

她在蹒跚学步时摔倒了。《柯林斯英汉双解大词典》

2·David rang up while you were out.

你不在的时候戴维打电话来了。《牛津词典》

3·Keep still while I brush your hair.

我给你梳头时你不要动。《牛津词典》

4·They met while on holiday in Greece.

他们是在希腊度假时认识的。《牛津词典》

5·I broke the vase while I was dusting.

我擦灰尘时将花瓶打碎了。《牛津词典》

6·I had a cigarette while I was waiting.

我等候时抽了一支烟。《牛津词典》

7·He gashed his leg while felling trees.

他砍树的时候割破了腿。《柯林斯英汉双解大词典》

8·Carry on with your work while I'm away.

我不在时你要接着干。《牛津词典》

9·He got work for a while detailing cars.

他找到一个清洗汽车的临时工作。《牛津词典》

10·They palled up while they were at college.

他们上大学时成了朋友。《牛津词典》

而

1·I went swimming while the others played tennis.

我去游泳，而其他人去打网球了。《牛津词典》

2·I walked back while the others rode in the car.

别人都乘车，而我是走回来的。《牛津词典》

3·Most digital camera owners are male, while women prefer film.

大部分数码相机的主人都是男性，而女性偏爱用胶卷。《柯林斯英汉双解大词典》

4·I remain to this day fluent in Hebrew, while my Arabic is atrocious.

我直到今天希伯莱语仍很流利，而我的阿拉伯语则极差。《柯林斯英汉双解大词典》

5·The team is in debt while others are lining up to cherry-pick their best players.

该队负了债，而别的队正在排队挑捡他们最好的运动员。《柯林斯英汉双解大词典》

虽然

1·The effects of global warming, while not immediate, are potentially catastrophic.

全球气温上升的后果虽然并非即时发生，但可能潜伏着大灾难。《牛津词典》

2·The trouble is that these restrictions have remained while other things have changed.

问题是，虽然其他事情已经改变，这些限制却依旧存在。《柯林斯英汉双解大词典》

3·The latest evidence suggests that while it isn't ideal, it might help.

最新证据表明，虽然这并不理想，但可能会有所帮助。

4·Sleeping pills, while helpful for some, are not necessarily an effective remedy either.

安眠药虽然对一些人有帮助，但也不一定是有效的治疗方法。

5·Another is that while nowadays reproduction is easy, it was not so easy in Roman times.

另一个原因是，虽然现在的复制很容易，但在罗马时代是不那么容易的。

尽管

1·For the remainder, the risk of cancer, while increased at the end of life, must be balanced with other factors like remaining life expectancy.

在剩下的时间里，尽管癌症的风险在临终时增加，它必须与其他因素平衡，如剩余预期寿命。

2·But for the remainder, the risk of cancer, while increased at the end of life, must be balanced with other factors like remaining life expectancy.

但在剩下的时间里，尽管癌症的风险在临终时增加，它必须与其他因素，如剩余寿命平衡。

3·At the same time, perhaps inevitably, the humanities—while still popular in elite colleges and universities—have experienced a significant decline.

与此同时，或许不可避免的是，人文学科——尽管在精英大学里仍然很受欢迎——已经经历了显著的下降。

4·According to a survey, while the majority believe too little assistance is given to the poor, more than a third believe too much is spent on welfare.

一项调查显示，尽管大多数人认为政府给予穷人的援助太少，但仍有超过三分之一的人认为政府在福利方面花费太多。

5·However, while Spaniards did put sugar, which was unknown to indigenous Americans, into chocolate beverages, this additive was not completely innovative.

然而，尽管西班牙人确实在巧克力饮料中加入了美国土著居民所不知道的糖，但这种添加剂并不是完全创新的。

趁

1·I got in an hour's work while the baby was asleep.

我趁孩子睡觉抽空干了一小时的活。《牛津词典》

2·Let me write it down while it's still fresh in my mind.

趁记忆犹新，我来把它写下来。《牛津词典》

3·What does it matter if I use his flat while he's away? What the eye doesn't see...!

我趁他外出时用他的公寓有什么关系呢？反正他又看不见！《牛津词典》

4·Oh, be warned, poor soul, and escape while you may.

啊，你要当心，可怜的人，趁你还来得及，赶快逃走吧。

5·You don't think I would kill him while he was sleeping!

你不要以为我趁他睡着时杀了他！

(1)after a while过了一会儿

(1)a little while不久，一会儿

(1)all the while一直；始终

(1)quite a while有一阵子，半天；相当长一段时间

(1)a while ago刚才，方才

(1)at whiles有时；间或；有时常常