A2
Saying the verb twice — 看看, 试试
Why Chinese repeats verbs — 看看, 想想, 试一试 — what the doubling actually does to the meaning, and why it is one of the quickest ways to stop sounding blunt.
Say a verb twice and the action becomes small: a brief go, a quick look, a try rather than an undertaking. It is one of the most characteristic things Chinese does, and one of the easiest to start using.
我看看。
Wǒ kànkan.
Let me have a look.
你试试。
Nǐ shìshi.
Give it a go.
我想想。
Wǒ xiǎngxiang.
Let me think about it.
The second copy is toneless. 看看 is kànkan, not kànkàn, and that unstressed second syllable is most of what makes it sound casual.
It is mostly about politeness
The literal effect is a bit, briefly. The practical effect is that the request stops being an instruction. 看 on its own is look; 看看 is have a look — same information, entirely different temperature. It does the same job as 一下 and the two are largely interchangeable.
你帮我看看这个。
Nǐ bāng wǒ kànkan zhège.
Could you have a look at this for me?
Two-syllable verbs double whole
A one-syllable verb repeats its syllable; a two-syllable verb repeats the whole word, with no toneless syllable in the middle.
我们休息休息吧。
Wǒmen xiūxi xiūxi ba.
Let’s take a bit of a break.
你介绍介绍。
Nǐ jièshào jièshào.
Tell us a bit about it.
AABB — 休休息息 — is not a thing. The unit that repeats is the word.
一 in the middle
一 can go between the halves of a one-syllable verb, and it makes the action even lighter and slightly more tentative.
你试一试。
Nǐ shì yi shì.
Just give it a try.
In the past, 了 goes in that slot instead: 我看了看, I had a quick look.
What cannot be doubled
The doubling means do a bit of this, so it needs a verb you can do a bit of. States and involuntary things refuse it: 是, 有, 知道, 喜欢, 死. 我喜欢喜欢 is not a sentence — you cannot like something briefly as an experiment.
Where you will use it
Offering, asking, softening, and buying yourself a moment. 我想想 and 我看看 are worth having ready as complete replies; both are what a native speaker says instead of standing there silently.