HSK 2 grammar · prefix
第
第 + number — ordinal numbers
Pattern
+ + +
( ) can be left out · other words may come before, between and after
How it works
第 before a number makes it an ordinal — first, second, third. A measure word usually still follows before the noun.
Examples
这是我第一次来中国。
Zhè shì wǒ dì-yī cì lái Zhōngguó.
This is my first time in China.
他住在第三层。
Tā zhù zài dì-sān céng.
He lives on the third floor.
Related

See it in a story
In the app, 第 is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.