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Ⅰ. affair “事、事情、事务”它的涵义最广，可指已经发生或必须做的任何事情， 也可泛指事务(通常用算数，指重大或头绪较多的事务)。如：
① The railway accident was a terrible affair. 那次火车事故是件可怕的事。
② That’s my affair, not yours. 那是我的事， 不是你的。
③ We should concern ourselves with state affairs. 我们要关心国家大事。
Ⅱ. matter“事、事情” 是普通用语，常指我们所写到或谈到的事情，要考虑和处理的事情。如：
① This is a matter I know little about. 这件事我不大知道。
② I’ll ask some one about the matter.关于这件事我将去问问人。
③ There are several matters to be considered. 有几件事情要考虑。
[注]：在口语中，be the matter 相当于 be wrong, 表发生了失常的事或出了毛病等意思。如：
① What’s the matter? 怎么啦?
② What’s the matter with you? 你怎么啦?
Ⅲ. business“生意、商业”产普通用语。它表“事情、事务”时，往往指一种任务、责任或必须去做的事。此外， 它有时还含有轻蔑的意味。如：
① We don’t do much business with them. 我们跟他们没有多少生意来往。
② It is a teacher’s business to help his pupils. 帮助学生是教师的责任。
③ He made it his business to fetch water for a granny. 他把为一位老大娘挑水当作自己的事。
④ It’s not your business.这不是你的事。
[注]：这三个词有时可通用，但不能任意替换。如：
Mind your own business.少管闲事。这里的 business 可用affairs 替换，但不能用 matters.
§12 afraid/ fear/ frightened
Ⅰ. afraid “害怕”是形容词，只能作表语，而不能作定语，后接of 短语或不定式，构成 be afraid of sb. 和 be afraid to do sth
① She is afraid of a snake. 她害怕蛇。
② The little girl is afraid to go out at night.
afraid +that clause “恐怕”， 是婉转拒绝别人的一种表达方式。 如：
① I’m afraid (that) I can’t go to the party. My brother is sick. 恐怕我不能去参加聚会了。我弟弟病了。
Ⅱ. fear “害怕”是动词，与be afraid 往往通用，但不如它常用(特别是在口语中)。如：
① We fear no difficulty.我们不怕困难。
② He feared to speak his mind.他不敢说出自己的想法。
③ Fearing that he would catch cold, I went out to see him.因为怕他会受凉，我走去看他。
Ⅲ. frightened adj “受惊吓的、害怕的”可做表语，也可作定语。如：
① She is too frightened to move.她太害怕了不能动弹。
② A frightened girl is crying. 一个受惊的女孩正在哭。
§13 feel like / would like
Ⅰ.feel like 与would like 意思很相近，但feel like 后面常跟名词;动名词。构成：feel like (doing) sth. 而 would like 一般接名词;动词不定式。构成：would like (to do) sth.的句式。如：
① I feel like (having) a drink. = I would like (to have) a drink. 我想喝一杯。
② Do you feel like talking a walk. = Would you like to take a walk? 你要不要散步?
③ I don’t feel like eating. 我不想吃东西。
Ⅱ.feel like 还表示：“觉得好像，摸起来像”。如：
① It feels like silk. 它摸起来像绸缎。
§14. after/behind “在……之后”
Ⅰ. after “在……(时间)之后”;
“在……(地点)之后”，指次序。如：
① He came after ten o’clock. 他十点以后来的。
② Two days after his arrival, I called on him. 在他到达两天以后，我拜访了他。
③ ‘Against’ comes after ‘again’ in this cictionary.在这本字典中 ‘against’ 排在 ‘again’ 之后。
Ⅱ. behind 表地点时意为：在……后面、着重指位置的前后。偶尔也指时间，表按照一定的时刻而迟了的意思。
① The garden is behind the house.
② He stood behind me.
③ The train was behind time. 火车误点了。
④ You are two hours behind. 你迟了两个小时。
§15. ago/before
Ⅰ. ago adv. “……以前”指从此刻起，若干时间以前，通常与过去连用。如：
① It happened two days ago.这件事发生在两天以前。
② I met him a few minutes ago.我在几分钟以前碰到他。
Ⅱ. before adv, prep & conj “……以前”指从那时起若干时间以前。通常与完成时、过去时等连用。还可用作前置词或连接词表时间，而ago 则不能这样用。
① He said that he had seen her two days before.他说他两天前见到过她。(表从她说话那时起两天前)
② I had been fine the day before.(那天)前一天的天气很好。
③ I’ve seen that film before.
④ I never met him before.
