用英语表达"a 是 b 的 n 倍长（宽，高，大，重等）"，"a 比 b 长（宽，高，大，重等）n 倍" 或"a 的长度（宽度，高度，大小，重量等）是 b 的 n 倍"，可用下列几种句型。

  1."a + be + 倍数 + as + 计量形容词原级 + as + b".
this tree is three times as tall as that one. 这棵树是那棵树的三倍高。
his father is twice as old as he. 他父亲的年纪有他两倍大。

  2."a + be + 倍数 + 计量形容词比较级 + than + b "
the yangtze river is almost twice longer than the pearl river.
长江差不多比珠江长两倍。
the dictionary is exactly five times more expensive than that one.
这本字典比那本恰好贵5倍。

  3."a + be + 倍数 + the + 计量名词 + of + b "
the newly broadened square id four times the size of the previous one.
新扩建的广场是未扩建时的四倍大。

  4."the + 计量名词 + of + a + be + 倍数 + that + of + b "
the size of the newly broadened square is four times that of the previous one.
新扩建的广场为以前的四倍大。

  5.其它
i'm twice/ double his age. 我的年龄是他的两倍。
i've paid five times the usual price for the stamp.
我出了5倍于往常的价格买这枚邮票。
 
the average income of the staff has been increased by 50 percent compared with last year. 与去年相比，该单位职工的收入增加了50%.
the price of tvs are twofold( adj. 两部分的, 双重的) down over these years.
近几年来，电视机的价格下降了两倍。