一下【yíxià】

一下 after a verb makes the action brief and low-key: you do it for a moment, without fuss. It goes straight after the verb.

Softening a request

Most of the time 一下 is about tone more than time. A request with 一下 asks for something small, so it sounds polite rather than bossy.

Where the object goes

A noun object follows 一下. A pronoun such as 我 or 他 goes between the verb and 一下.

• × 看这个一下 → 看一下这个

With 了

For something already done, 了 goes between the verb and 一下.

• × 我看一下了 → 我看了一下

Doubling the verb, as in 看看, does much the same job and has its own point.