Ordinal number

The prefix dì 第 is placed before a number to indicate an order or a sequence, turning cardinal numbers into ordinal numbers. For example, dì-yī  第一 corresponds to ‘first’ in English, and dì-èr 第二 corresponds to ‘second’.

Like cardinal numbers, ordinal numbers can also be placed before measure words in Chinese. For example, dì-yī  ge rén 第一个人/第一個人 corresponds to ‘the first person’ in English, and dì-èr běn shū 第二本书/第二本書corresponds to ‘the second book’.

Structure

Functions

Indicating an order or a sequence

The structure dì 第 + number is used when it is necessary to indicate sequence or order explicitly.

The prefix dì 第 can only be followed by èr 二, never by liǎng 两/兩. For example, liǎng bēi chá 两杯茶/兩杯茶 means ‘two cups of tea’, whereas dì-èr bēi chá 第二杯茶 means ‘the second cup of tea’.

Note that some nouns, such as tiān 天 ‘day’, nián 年 ‘year’, zhōu 周/週 ‘week’, kè 课/課 ‘lesson’, jù 句 ‘sentence’, can serve as measure words. The ordinal structure dì 第 + number may be placed directly before these nouns, with no extra measure word required.

In many European languages, ordinal numbers are commonly used to refer to floors of buildings, such as “the first floor” in English. In Chinese, however, ordinal forms are not used to refer to building floors. Instead, a cardinal number is placed directly before the noun lóu 楼/樓 ‘floor (of a building)’ or céng 层/層 ‘floor (of a building)’.

Ordinal numbers are also not used when referring to a specific month such as February or March. For example, February is èr yuè 二月, whereas dì-èr ge yuè 第二个月/第二個月 means ‘the second month’.