荐for__because_since区别;但是的区别;

第三部分
Grammar:Link Words
连词although_but_while和however
请观察下列句子, 注意总结while和although的用法。
1. Schools in the north are well-equipped, while those in the south are poor. 2. While I’m cleaning the floor, you can clean the windows. 3. While we don’t agree with each other, we continue to be friends. 4. Although born in Chicago, the author is most famous for his stories about New York City. 5. Although he said he was ill, yet I saw him in the street just now.

第二部分
aim, goal, purpose, end, target, object, objective
aim, goal, purpose, end, target, object, objective




这些名词均有“目标、目的”之意 aim ：从本义“靶子”引申而来，侧重比较具体 而明确的目标，但常指短期目标。 goal ：指经过考虑和选择，需经坚持不懈的努力 奋斗才能达到的最终目标。 purpose ：普通用词，既指以坚决、审慎的行动 去达到的目的，又指心中渴望要实际的目标。 end ：指心目中怀着的某种目的，强调结果而非 过程。较正式用词。 target ：指射击的靶，军事攻击目标。引申指被 攻击、批评或潮笑的目标。
【总结归纳】 but与however都表示“但是，然而”， 都可以引导并列句，但二者用法有些区别。 1. 从语义上看，but所表示的是非常明显 的对比，转折的意味较however要强。 2. 从语法上看，but是个并列连词，而 however是个连接副词。 3. 从语序上看，but总是位于它所引出的 分句之首，而however却可位于分句之首、 之中或之尾。 从标点上说，but之后一般不使用逗号，但 however则通常用逗号与句子其他部分 分开。
二、请观察下列句子，注意总结 however和but的用法。 1. I was going to write you a letter, but I lost your address. 2. However, I can discuss this all when I see you. 3. He said that it was so; he was mistaken, however. 4. He hasn't arrived. He may, however, come later.

as是常用词，它表示的“原因”是双方已知的事 实或显而易见的原因，或者理由不是很重要，含 义与since相同，但语气更弱，没有since正式， 常译为“由于，鉴于”。从句说明原因，主句说 明结果，主从并重。 (1)We all like her as she is kind. 我们都 喜欢她，因为她善良。 (2)As I had a cold, I was absent from school. 因为我感冒了，所以没去上课。 (3)As Xiaowang was not ready, we went without him. 由于小王没有准备好，我们 只好不带他去了
3. —Are you ready for Spain? —Yes, I want the girls to experience that _____ they are young. A. while B. until C. if D. Before 4.We had to wait half an hour _____ we had already booked a table. A. since B. although C. until D. Before 5.Although badly hurt in the accident, the driver was _____ able to make a phone call. A. still B. even C. also D. Ever
第一部分
for,because,as,since
because ,for ,as ,since 表示“因为”时的区别
because, as, for, since这几个词都是表示 “原因”的连词，语气由强至弱依次为： because→since→as→for;其中because, since, as均为从属连词，引导原因状语从 句；而for 是并列连词，引导并列句。
练习：
一、从A、B、C、D四个选项中，选出可以填入空白 处的最佳选项。 1._____ the Internet is of great help, I don’t think it’s a good idea to spend too much time on it. A. If B. While C. Because D. As 2.In some places women are expected to earn money _____ men work at home and raise their children. A. but B. while C. because D. Though
since侧重主句，从句表示显然的或已为人所知 的理由，常译为“因为”、“既然”，语气比 because稍弱，通常置于句首，表示一种含有勉 强语气的原因。例如： (1)Since he asks you, you”ll tell him why. 他既然问你，那就告诉他为什么吧。 (2)Since everyone is here, let”s start. 既然大家都到齐了，我们就出发吧！ (3)Since I understood very little Japanese, I couldn”t follow the conversation. 我日语懂得不多，因而听不懂对 话。
Keys： Ⅰ. 1. However 2. but 3. Although 4. however 5. but 6. while 7. However 8. but
Ⅱ. 单项填空。 1. — Someone wants you on the phone. — nobody knows I am here. [2011年全 国I卷] A. Although B. And C. But D. So 2. regular exercise is very important, it’s never a good idea to exercise too close to bedtime [2011年天津卷]. A. If B. As C. Although D. Unless 3. you may have, you should gather your courage to face the challenge. [2010年上海卷] A. However a serious problem B. What a serious problem C. However serious a problem D. What serious a problem
Ⅰ. 用but，however，although和while填空。
1. , they did not seem to have much effect. 2. He drives not carefully slowly. 3. many difficulties are still ahead, we are determined to make greater achievements. 4. He said that it was so; he was mistaken, . 5. He looks honest, actually he’s a rogue (无赖). 6. He went out for a walk, I stayed at home. 7. cold it is, she always goes swimming. 8. I’m very sorry, I can’t see you today

for用作连词时，与because相似，但它所表示 的原因往往提供上文未交待过的情况。for不表 示直接原因，表明附加或推断的理由，因此for 被看作等立连词，它所引导的分句只能放在句子 后部(或单独成为一个句子)，并且前后两个分句 间的逻辑关系不一定是因果关系，其间用逗号隔 开，且for不可置于句首，for的这一用法常用在 书面语中，较正式。 (1)The days are short, for it is now December. 白天短了，因为现在已是十二月份。 (2)It must have rained, for the ground is wet. (从“地面潮湿”作出“下过雨”的推测， 但地湿并不一定是下雨所致, for不可以换为 because。) (3)The ground is wet because it has rained. (“下雨”是“地上潮湿”的直接原因。)


1. because表示直接原因，它所指的原因通常是听 话人所不知道的，其语气最强。常用来回答why的 提问，一般放于主句之后，也可以单独存在。 (1)I stayed at home because it rained. 因 为下雨我呆在家里。 (2)Because Lingling was ill, she didn”t come to school. 玲玲因病，没有上学。 (3)Why is she absent? 她为什么缺席？ Because she is sick. 因为她病了。 此外，在强调句型中，只能用because。例如： (4)It was because I missed the early bus that I was late for school. 我上学迟到是因为我 没有赶上早班汽车。
【总结归纳】
1. while的用法： 1ቤተ መጻሕፍቲ ባይዱ表示对比，意为“而；然而”。 2）引导时间状语从句，意为 “当……时候；在……期间”，强调 某一段时间内主句 和从句的动作在同一时期发生， while从句中的动词通常是延续性动词。 3）引导让步状语从句，意为“虽 然，尽管”，多放在句首。
2. although的用法： although为从属连词，意为“虽然，尽管”， 引导让步状语从句。注意以下两点： 1）although在大多下数情况下可与 though通用，但在正式文体中，though可用 于 一 种不以其为首的让步状语从句，这种从句 须以形容词、名词或动词（原形） 等开 头，整个从句须置于主句之前。这时 although不能替换though。如： Tired though he was, he went on working.（他虽然累，但还是继续工作。） 2）although所引导的从句不能与but， and，so，however等连用，但可以和副词yet， still等连用。

前后两个分句间有一定的因果关系时(有时 很难区分是直接原因，还是推测性原因)， for与because可以互换使用. (4)I could not go, for / because I was ill. 我没能去，是因为我病了。 (5)He felt no fear, for / because he was a brave boy. 他没有害怕，因为他是个 勇敢的男孩