Ordinal Numbers: 第 + Number
序数表达法
Build first, second, third … using 第 + number + (measure word + noun)
Place 第 (dì) before any number and you have an ordinal: 第一 (first), 第二 (second), 第十 (tenth). To rank a noun, add the standard measure word and the noun: 第一个朋友 (the first friend), 第三课 (lesson three).
The number after 第 is the ordinary 一 / 二 / 三 (NOT 两). Some category nouns swallow the measure word: 第三课 needs no 个; 第一名 needs no 个.
Lesson Targets
Podcast
Podcast: Ordinal Numbers: 第 + Number (序数表达法)
Listen to Jason & Amy explain the 序数表达法 pattern
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Understanding 序数表达法
English uses suffixes for ordinals (first, second, third…) and they're wildly irregular. Chinese is far kinder: just glue 第 (dì) onto the cardinal number and you have an ordinal. 第一, 第二, 第三, …, 第一百. The pattern never breaks. The HSK 3.0 syllabus pulls this out as "序数表达法1" at level 1 because ordinal expressions are everywhere — lesson numbers, floor numbers, rank, sequence, queue position. Once you can build 第+number, you can read schedules and signage all over China.
Key Points
- Basic ordinal: 第 + number. 第一 (first), 第十 (tenth), 第一百 (hundredth).
- Use 一 (not 两) after 第, even before a measure word: 第一个 (the first one), not 第两个.
- For things, add measure word + noun: 第一个朋友, 第二本书, 第三个孩子.
- Category nouns that double as measure words skip 个: 第三课 (lesson 3), 第一名 (first place / rank), 第二楼 (second floor).
- For dates and lesson numbers in writing: 第一课, 第二章, 第三节.
- Asking "which one (in order)?": 第几 + measure word + noun. 你是第几个？(Which one in line are you?)
- "Last" is not 第后 — it's 最后. 最后一个 (the last one), 第一个 (the first one).
- For floors: 第 + number + 层 / 楼. 我住在第三层 (I live on the third floor).
In Chinese sequencing, you'll often see 第一、第二、第三 listed at the start of bullet points in news, instructions, and speeches — equivalent to "first… second… third…" in English. Mastering this prefix instantly improves your reading of any structured Chinese text.
Key Vocabulary
Example Sentences
今天是第一课。
Today is Lesson 1.
第 + number + category noun (课). No 个 needed.
你是我第一个朋友。
You are my first friend.
第 + number + 个 + noun.
我们住在第三层。
We live on the third floor.
他考了第一名。
He came in first place on the exam.
名 doubles as measure word.
这是我第三次来北京。
This is my third time coming to Beijing.
Ordinal of times: 第 + number + 次.
请坐第二排。
Please sit in the second row.
你是第几个？
Which one in line are you?
Question: 第几 + measure word + noun.
他是我们班的第十名。
He's tenth in our class.
第一次见面，请多关照。
Nice to meet you (lit. "first meeting, please take good care").
Set polite greeting using ordinal + 次.
最后一个问题是什么？
What's the last question?
"Last" uses 最后, not an ordinal.
Common Mistakes
After 第, the number is always 二 — never 两. The 一 / 两 distinction does not apply inside ordinals.
课 is its own measure-noun. 第+number+课 needs no 个 in between.
"Last" is 最后, NOT an ordinal with 第. 第 only builds ordered positions from 1 upward.
Practice Exercises
Tips & Tricks
Ordinal recipe: 第 + cardinal number. The number stays the everyday 一 / 二 / 三 — never switch to 两.
If the noun is a category noun (课, 名, 楼, 层, 排), it acts as its own measure word — skip 个.
For people and most other nouns, use 第 + number + 个 + noun: 第一个朋友, 第二个孩子.
"Last" is 最后, not an ordinal. Only forward-counting positions use 第.
Homework
Write six sentences with ordinals: two using 第 + 课 (lesson numbering), two using 第 + 个 + person/object, one with 第 + 次 (nth time doing something), and one question with 第几.