▎一下 A，一下 B, (yíxià A, yíxià B), referring to alternating events

 

Function 下 is a verbal measure, referring to very brief moments in time. This pattern describes the speaker’s slight displeasure at fast-changing scenes, of usually two activities.

1 你別一下吃熱的，一下吃冰的，肚子會不舒服喔！

Nǐ bié yíxià chī rè de, yíxià chī bīng de, dùzi huì bú shūfú o!

Don’t eat hot and cold foods in such close succession like that. You’ll get a stomache ache.

2 這個地方天氣還真怪，一下冷，一下熱。

Zhè ge dìfāng tiānqì hái zhēn guài, yíxià lěng, yíxià rè.

The weather here is rather unpredictable; one moment it’s cold, the next it’s hot.

3 我女朋友一下要我陪她去看電影，一下要我陪她去逛夜市。她到底想去哪裡？

Wǒ nǚpéngyǒu yíxià yào wǒ péi tā qù kàn diànyǐng, yíxià yào wǒ

péi tā qù guàng yèshì. Tā dàodǐ xiǎng qù nǎlǐ?

My girlfriend wants me to go with her to the movies one moment, then to the night market the next. I have no idea where she actually wants to go.

4 感冒的時候一下咳嗽，一下流鼻水，真不舒服。

Gǎnmào de shíhòu yíxià késòu, yíxià liú bíshuǐ, zhēn bù shūfú.

Having a cold is terrible, constantly coughing and having a runny nose.

5 你一下寫功課，一下跟朋友玩，功課當然寫不完。

Nǐ yíxià xiě gōngkè, yíxià gēn péngyǒu wán, gōngkè dāngrán xiěbùwán.

If while you are doing your homework you chat with your friends every few minutes, of course it’ll never get done.

 

Usage 一下 as combined, serves like an adverb. As illustrated above, it does not connect instances in negation.