★ my shoes are worn out.
my shoes are worn out.我的鞋穿破了。
be worn out 表示“穿破了”，这个词组看起来是被动形式，但并不强调被动，强调的是状态或者情况，可以理解为形容词短语。例如：
my clothes are worn out and i have to mend them.
我的衣服穿破了，我得补一下。
you see,this glass is broken.
你瞧，这个杯子破了。
★ you'd better buy a new pair.
you'd better buy a new pair.你最好买一双新的。
a pair of…表示“一对”，“一双”，指一起使用的两个相同的东西。例如：
have you bought a pair of shoes?
你买了一双鞋吗？
this pair of glasses is very good for me.
这副眼镜我戴很好。
★ that's a bit expensive.
that's a bit expensive.价钱有点贵。
a bit 表示“一点儿”，“有些”，在句中作定语或者状语，相当形容词或者副词。与a little 是同义词。例如：
it's a bit cold today;you'd better put on more clothes.
今天有点冷，你最好多些穿衣服。
if you study a bit hard,you can pass the exam.
如果你多一点努力学习，你就能考试及格。
please give me a little water.
请给我一点儿水。
★ the shop was quite new,for it had opened only the week before.
the shop was quite new,for it had opened only the week before.因上周才开张的，所以商店很新。
for 表示“因为”，相当于because 和as.表明原因，三个词中，because语气最强，for 语气最弱。for 表明的原因要写在后面。例如：
i want to go to bed,for i feel tired.
我想去睡觉，因为我感到累了。
"why didn't you come to school?""because i was ill."
“为什么你昨天没来学校？”“因为我病了。”
as it is raining,i am not going shopping.
天下雨了，我就不买东西了。
★ they were either too big or too small.
they were either too big or too small.它们不是太大就是太小。
either…or…表示“不是…就是…”，“或者…或者…”，可连接两个并列成分或句子。例如：
she is either lucy or lili.
她不是露西就是莉莉。
either you or i am wrong.
不是你就是我错了。
★ they were so pleased to see each other that they forgot everything else.
they were so pleased to see each other that they forgot everything else.他们见面后太高兴了，以致于把一切事情都忘了。
so…that…表示“如此…以致于…”。so 后面接形容词或副词，that 后面跟一结果从句。例如：
it's so cold that i have to put on more clothes.
天太冷了，我不得不多穿衣服。