Comparing "er" and "liang"
Structure
In Chinese, there are two words for two.
The digit 2 is 二 (èr). This is used generally in numbers, when counting to ten and so on. When specifying quantities, however, 两 (liǎng) is used. This is when you want to say "two of" something.
A good rule is that if a measure word is used, use 两. 二 does not generally occur with measure words.
Also remember that two o'clock uses 两: 两点. It's two points on the clock, which is a quantity, so 两 is used.
Examples
Here are some common examples of 二 in action:
- 第 二 #2; second
- 第 二 个 the second one
- 二 号 #2; the second (of the month)
- 二 号 线 Line 2 (as of a subway)
- 二 楼 floor 2
- 二十二 22
- 二百 (note: 两百 is also acceptable.)) 200
Here are some common examples of 两 in action:
- 两 个 人 two people
- 两 年 two years
- 两 个 月 two months
- 两 天 two days
- 两点 2 o'clock
- 两百 (note: 二百 is also acceptable.)) 200
- 两千 2,000
- 两万 20,000
