一、用“平级”或“比较级”表达倍数

　　表达倍数时，既可以用“平级”，也可以用“比较级”。

　　如：A楼的高度是B楼的三倍(A楼比B楼高两倍)。

　　Building A is three times as tall as Building B. (平级)

　　Building A is three times taller than Building B. (比较级)

　　在倍数比较的句子中，常见的错误之一，是形容词与其所修饰的名词不搭配。

　　例如：

　　The population of China is five times as big as that of Pakistan. √

　　The population of China is five times as many as that of Pakistan. ×

　　在汉语里，可以用“多”和“少”来形容人口，于是很多人会用as many as。而句中的主语是population, 只可以用large/big/small来形容。

　　二、百分数的表达percent or percentage?

　　◆Percent : it is used to express proportions out of a hundred. Percent is always used with a number.

　　2 percent = 2%

　　percent = per centum

　　数词+percent+of+sth：后面谓语的单复数以percent后面跟接的主语(sth)为主

　　例如:

　　20 percent of the apples are eaten. (这里是复数的可数名词，所以用复数。)

　　20 percent of the water is drunk.(这里是不可数名词，所以用单数。)

　　◆Percentage: portion or amount of something

　　The percentage of +sth+ is：注意这里不管后面跟的是什么词,都用第三人称单数

　　The percentage of the students is 46.

　　The percentage of the water is 46.

　　That was a high percentage.

　　常见错误：

　　Percent is only used after a number. If you are referring more generally to part of an amount, use percentage.

　　Percent仅用在数字之后，如果更笼统表示数量中的一部分，可用percentage:

　　A high percentage (不说percent) of the population was illiterate.

　　绝大部分人口是文盲。

　　三、时间介词at on in

　　◆at用在时间点前：

　　The lecture is at 7.00.

　　◆on用在星期和日期前：

　　The lecture is on Thursday.

　　The lecture is on 27 October.

　　◆in用在时间段，月份，年和季节前：

　　The lecture is in the morning.

　　The lecture is in June.

　　The lecture is in 2004.

　　The lecture is in winter.

　　我们把这几个时间介词都放在一句话中：

　　The lecture is at 7.00, in the morning, on Thursday, on 27 October, in 2004.