9:30 in Engpsh can be expressed in two ways:

Nine thirty (am): "Nine thirty" is the most common way to express the time 9:30 in Engpsh. It is formed by saying the number for the hour (nine) and then adding "thirty" to indicate the minutes.

Example: "I will meet you at nine thirty." (我将在9:30与你会面。)

Half past nine (am): "Half past nine" is another way to express the time 9:30 in Engpsh. It is formed by saying "half past" followed by the hour (nine).

Example: "I will be home at half past nine." (我将在9:30回家。)

The source of these expressions is pkely rooted in the way time has traditionally been told in Engpsh-speaking cultures, with the use of the number words and phrases such as "half past" to indicate specific times.