二 vs 兩: When to Use Each in Chinese

Use 二 (èr) when you are saying the number itself: counting, reading digits, naming a month, floor or place in a sequence. Use 兩 (liǎng) when you are saying “two of something” and a measure word follows: 兩個人 (liǎng ge rén), 兩杯咖啡 (liǎng bēi kāfēi). Those two rules cover most sentences you will ever say.

The remaining cases come down to a few patterns that are worth learning once, because the two words are not interchangeable.

The two core rules

Situation	Use	Example
Counting aloud, digits, labels	二	一、二、三; 二樓 (èr lóu, second floor)
Ordinals	二	第二 (dì’èr, second)
Quantity + measure word	兩	兩本書 (liǎng běn shū, two books)

Examples with measure words:

• 我有兩個孩子。 Wǒ yǒu liǎng ge háizi. “I have two children.”
• 請給我兩杯咖啡。 Qǐng gěi wǒ liǎng bēi kāfēi. “Two coffees, please.”
• 我買了兩張票。 Wǒ mǎi le liǎng zhāng piào. “I bought two tickets.”

✗ 我有二個孩子。

✗ 請給我二杯咖啡。

Both are ungrammatical. The MOE dictionary lists 兩 as a number word meaning a pair, with the examples 兩本書 and 兩姊妹, which is exactly this use. If measure words are still shaky, Chinese measure words covers the structure.

Where 二 is the right choice

Counting and digits

When you count out loud, you say 一、二、三. The same goes for reading a number digit by digit: 二〇二六年 (èr líng èr liù nián), “the year 2026”. Phone numbers are also read digit by digit, and the 2 is 二.

Dates, days and floors

• 二月二號 Èr yuè èr hào, “February 2nd”
• 星期二 Xīngqí’èr, “Tuesday”
• 二樓 Èr lóu, “second floor”

Floors work like labels, so “second floor” is 二樓, never 兩樓.

Ordinals and sibling order

• 第二課 Dì’èr kè, “Lesson 2”
• 二哥 Èr gē, “second-eldest brother”

The ordinal marker 第 always takes 二: 第二, and never ✗ 第兩.

Tens and units inside a number

In the middle of a number, 二 is the digit:

• 十二 shí’èr, 12
• 二十 èrshí, 20
• 二十二 èrshí’èr, 22

✗ 兩十 is not said for 20. When 兩 appears in a number, it sits in front of 百, 千, 萬 or 億, which is the next topic.

Where 兩 is the right choice

As a time quantity

Quantities of time follow the same logic as other nouns:

• 兩個小時 liǎng ge xiǎoshí, “two hours”
• 兩個星期 liǎng ge xīngqí, “two weeks”
• 兩個半小時 liǎng ge bàn xiǎoshí, “two and a half hours”

The clock hour is a special case. “Two o’clock” is 兩點 (liǎng diǎn), because 點 (o’clock) takes 兩 like a measure word does. “Two twenty” is 兩點二十分 (liǎng diǎn èrshí fēn): 兩 before 點, 二 in the minutes.

”A couple of”

兩 can also be a loose “a few”. The MOE dictionary lists this sense, glossed 幾、若干, with the example 過兩天再看看, “I’ll look again in a couple of days”.

• 我過兩天再打給你。 Wǒ guò liǎng tiān zài dǎ gěi nǐ. “I’ll call you back in a couple of days.”

Here 兩 is not an exact count, so don’t translate it as “exactly two”.

Both of two

When the number of people is two and you mean both, 兩 is again used:

• 我們兩個都喜歡這家店。 Wǒmen liǎng ge dōu xǐhuān zhè jiā diàn. “Both of us like this shop.”

兩百 and 二百, 兩千 and 二千

Usage varies here, so this section separates what is firm from what is flexible.

Firm: a number that starts with 2 before 百, 千, 萬 or 億 takes 兩 when you give a quantity or amount, especially in speech.

• 兩百塊 liǎng bǎi kuài, NT$200
• 兩千塊 liǎng qiān kuài, NT$2,000
• 兩萬 liǎng wàn, 20,000
• 兩億 liǎng yì, 200 million

Flexible: 二百 and 二千 are understood, and in Taiwan 兩百 is the everyday spoken form for an amount. For a learner, the safe habit is 兩 at the front of a number before 百, 千, 萬 and 億, and 二 for every digit or label.

Inside a larger number, after another unit, both forms are heard. 1,200 can be 一千兩百 (yì qiān liǎng bǎi) or 一千二百 (yì qiān èr bǎi), and the spoken short form 一千二 is common. Chinese numbers gives 一千二百. A trailing 2 is always 二:

• 2,222 can be said 兩千兩百二十二 or 兩千二百二十二 (liǎng qiān èr bǎi èrshí’èr). Both are fine.

Money is where this matters most for living in Taiwan. A price of NT$2 is 兩塊, NT$20 is 二十塊, NT$200 is 兩百塊. The full number system, including 萬, is in Chinese numbers.

A few more edge cases

• Fractions use 二: 二分之一 (èr fēn zhī yī), “one half”. People more often just say 一半 (yíbàn) for “half”.
• Decimals read the digit: 零點二 (líng diǎn èr), 0.2.
• 兩 is also a unit of weight. The MOE dictionary lists it as a measure of weight (a tael). The unit itself takes 二, so “two taels” is 二兩, never ✗ 兩兩. You may meet this at a traditional market or herbal shop.
• 倆 (liǎ) means “two people” and is a contraction of 兩個. The MOE lists it with the gloss 兩個, but it is rare in Taiwan writing, so 我們兩個 is the form to learn.
• 一兩個 (yì liǎng ge) means “one or two”: 我只要一兩個. The 兩 here is the loose “a couple” sense.
• With 半: 兩個半小時 (two and a half hours) puts 半 after the measure word, while 半小時 (half an hour) has no 兩 at all.

Common mistakes

Mistake	Fix
✗ 二個人	兩個人
✗ 第兩	第二
✗ 兩月 for February	二月
✗ 二點 for 2 o’clock	兩點
✗ 兩十 for 20	二十

A memory shortcut

Ask one question: is there a measure word, or something acting like one, right after the number? If yes, use 兩. If you are naming, counting out loud, reading digits, or placing something in a sequence, use 二. 星期二 and 二月 are names. 兩個星期 is a quantity, even though both contain 星期.

Related reading

• Chinese measure words
• Chinese numbers: 1 to 10, big numbers and 萬
• 有點, 一點, 一些, 一下: softening in Chinese