用
yòng
Why 'don't mention it' starts with 用
The picture You pick something up and borrow its power to get the job done. 拿 gets the chopsticks into your hand; 用 borrows the chopsticks' power to lift the food.
Where the picture shows up in 用
-
borrow a tool's power
可以用微信付款吗？
kěyǐ yòng wēixìn fùkuǎn ma
Can I pay by WeChat?
You hold the phone up to the QR code and its power settles the bill for you.
-
work the thing
这台机器怎么用？
zhè tái jīqì zěnme yòng
How do you operate this machine?
You take hold of the lever, press the button, and the machine turns over.
-
no need to spend anything on it
不用谢。
bú yòng xiè
Don't mention it.
A hand waves the offered help away: nothing needs to be spent here.
不用 literally says 'no need to expend' — that's why it does the work of declining an offer.
-
spend your attention
做事用点心，别马虎。
zuò shì yòng diǎn xīn, bié mǎhu
Put your mind into it — don't be careless.
Your eyes narrow onto one spot and your attention runs all the way out to your fingertips.
-
put money where it goes
这笔钱用在孩子的学费上。
zhè bǐ qián yòng zài háizi de xuéfèi shàng
This money goes toward the kids' tuition.
The money comes out of the envelope and lands straight on the school's payment slip.
All of it in one picture
用 is picking something up and borrowing its power to get a thing done. The phone's power settles the bill; the machine's power turns the work over. Wave the whole transaction away — nothing at all needs to be spent — and you have 不用, which is how Chinese declines. What you borrow doesn't have to be an object: you can spend your attention and spend your money the same way, so every 用 comes with the question of what was put in to make the thing happen.