兩 + Classifier

Cantonese distinguishes between the digit 'two' and the quantity 'two' based on specific conventions.

1. Quantity vs. Sequence
Use 兩 (loeng5) when you are talking about an amount or quantity. This almost always happens in the counting frame. For example, 'two people' is 兩個人 (loeng5 go3 jan4). Note that the noun can be omitted if it's understood from context (e.g., 'I want two [of them]' = 我要兩個 ngo5 jiu3 loeng5 go3), and 兩 is still required.
Use 二 (ji6) for sequences (like 第二 dai6 ji6 - the second), labels (Room 2), or dates like 'February' (二月 ji6 jyut6). Contrast this with a duration or quantity, such as 'two months' (兩個月 loeng5 go3 jyut6), which requires 兩.

2. Compound Numbers Ending in 2
While 兩 (loeng5) is used for the quantity of two, any number greater than 10 that ends in 2 must use 二 (ji6), even before a classifier. For example, 'twelve people' is 十二個人 (sap6 ji6 go3 jan4), and 'thirty-two' is 三十二 (saam1 sap6 ji6).

3. Large Numbers, Money, and 廿 (jaa6)
For 200, 2,000, and 20,000, both 兩 (loeng5) and 二 (ji6) are perfectly acceptable and extremely common in everyday spoken Cantonese (e.g., 兩百 loeng5 baak3 or 二百 ji6 baak3).
However, for 20, spoken Cantonese uses the colloquial word 廿 (jaa6). Therefore, 22 is usually spoken as 廿二 (jaa6 ji6), and '20 people' is 廿個人 (jaa6 go3 jan4).
When counting money, 'two dollars' is 兩蚊 (loeng5 man1), but 'twenty dollars' is 二十蚊 (ji6 sap6 man1) or 廿蚊 (jaa6 man1).

4. Technical Contexts and Exceptions
Always use 二 (ji6) for:

• Decimals: 零點二 (ling4 dim2 ji6) - 0.2
• Fractions: 三分之二 (saam1 fan6 zi1 ji6) - two-thirds
• Digit strings: Phone numbers or ID numbers are read digit-by-digit using 二 (ji6).
• Weight exception: When using the traditional measure word for weight, a tael (兩 loeng2), you must say 二兩 (ji6 loeng2), never 兩兩.

5. Time, Age, and Half
Words for time like 'o'clock' (點 dim2) act as classifiers, so they require 兩 (loeng5). For example, 'two o'clock' is 兩點 (loeng5 dim2). For minutes, Cantonese often uses the clock-face numbers where 1 means 5 minutes, 2 means 10 minutes, etc. So, 1:10 is 一點二 (jat1 dim2 ji6) because the minute hand is on the 2. Alternatively, using the measure word 字 (zi6) for 5-minute intervals, 1:10 is expressed as 一點兩個字 (jat1 dim2 loeng5 go3 zi6). For exact minutes, the word 分 (fan1) is used, and the digit 2 is read as 二 (ji6) (e.g., 1:02 is 一點零二分 jat1 dim2 ling4 ji6 fan1). For time durations, you must use 兩 (loeng5) with the appropriate classifier. For example, 'two hours' is 兩個鐘 (loeng5 go3 zung1) or 兩小時 (loeng5 siu2 si4), and 'two minutes' is 兩分鐘 (loeng5 fan1 zung1).
For 'year' (年 nin4), 'age' (歲 seoi3), and 'days' (日 jat6 / 天 tin1), these act as their own classifiers and take 兩 for duration or quantity (e.g., 兩年 loeng5 nin4 = two years; 兩歲 loeng5 seoi3 = two years old; 兩日 loeng5 jat6 = two days). For calendar years, the digits are read using 二 (e.g., the year 2026 is 二零二六年 ji6 ling4 ji6 luk6 nin4).
When combining with 'half' (半 bun3), you use 兩 for 2.5 (兩個半 loeng5 go3 bun3 - two and a half). But for compound numbers ending in 2, the rule for compound numbers overrides this, so 12.5 is 十二個半 (sap6 ji6 go3 bun3).

6. Idiomatic Use: "A Few"
In casual Cantonese, 兩 (loeng5) is often used idiomatically to mean "a few" or "a couple of", rather than exactly two. For example, 過兩日 (gwo3 loeng5 jat6) means "in a few days", and 講兩句 (gong2 loeng5 geoi3) means "say a few words". You will also see 兩 used in the 'one or two' approximation pattern, such as 一兩日 (jat1 loeng5 jat6 - one or two days) or 一兩個人 (jat1 loeng5 go3 jan4 - one or two people), where 二 cannot be used.