4:30 in English is usually said as "four thirty" or "half past four." The way that time is expressed in English comes from the way that hours are counted in the 12-hour clock system. In this system, the day is divided into two 12-hour periods: am and pm. The am period runs from midnight to noon, and the pm period runs from noon to midnight. In the 12-hour clock system, the hours are numbered from 1 to 12, and the minutes are typically expressed in terms of the hour that they are closest to. For example, 30 minutes past the hour is usually referred to as "half past" the hour, 45 minutes past the hour is "quarter to" the next hour, and 15 minutes past the hour is "quarter past" the hour.

Here are some example sentences using the phrase "four thirty" in English:

I have to be at work by four thirty.

Can you come over for dinner at four thirty?

The movie starts at four thirty, so we should leave now.

In Chinese, 4:30 is typically expressed as "四点半" (sì diǎn bàn) or "半个小时过四点" (bàn gè xiǎo shí guò sì diǎn). Some example sentences using this phrase in Chinese are:

我必须在四点半之前到达工作地点。(Wǒ bìxū zài sì diǎn bàn zhīqián dàodá gōngzuò dìdiǎn.)

你能在四点半来吃晚餐吗？(Nǐ néng zài sì diǎn bàn lái chī wǎncān ma?)

电影在四点半开始，所以我们现在就应该出发。(Diànyǐng zài sì diǎn bàn kāishǐ, suǒyǐ wǒmen xiànzài jiù yīnggāi chūfā.)