We can use the words for dates to indicate duration.

The words 年 nin4 (‘year’) and 日 jat6 (‘day’) are measurement unit classifiers. They are used alone without a noun. We simply put the number of years or days before them.

The word 月 jyut6 (‘month’) is a noun instead of a classifier. We add the classifier 個 go3 between the number and 月 jyut6.

We say 兩 loeng5 instead of 二 ji6 for ‘two’ because we are indicating a quantity.

The word 半 bun3 means ‘half’. We can put it before the classifier to mean ‘half a …’.

We put 半 bun3 after the classifier to indicate a number and a half. Notice for months, we put 半 bun3 after 個 go3.

When we put 半 bun3 after the classifier and the number is 一 jat1 (‘one’), we can optionally omit the number.

The word 幾 gei2 means ‘several’. We can put it before the classifier to mean ‘several …’. 幾 gei2 here usually refers to a quantity between 3 and 9 inclusive.

We can put 幾 gei2 after 10, 20, 30, etc. to mean ’10, 20, 30 something, etc.’. 幾 gei2 here also usually refers to a quantity between 3 and 9 inclusive.

We can also put 幾 gei2 after the classifier to mean ‘… and slightly more’. Notice for months, we put 幾 gei2 after 個 go3. We usually use 幾 gei2 this way with a small number, usually not larger than 10.

When we put 幾 gei2 after the classifier and the number is 一 jat1 (‘one’), we can optionally omit the number.

Notice the meaning changes depending on whether 幾 gei2 is put before or after the classifier.