住
zhù
住 has nothing to do with living somewhere. It is a grip
The picture A hand closing around something in motion and pinning it where it is. It can no longer move or slip away. 住 catches something and fixes it in place; 开 lets go so it opens up — 抓住 and 放开 are the two ends.
Where the picture shows up in 住
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feet pinned
站住！别跑。
zhàn zhù! bié pǎo
Stop right there! Don't run.
Running feet stopping dead as if nailed to that exact spot.
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held by hand
上车快抓住扶手。
shàng chē kuài zhuā zhù fúshǒu
Hold on to the rail once you're on.
Fingers wrapping the rail so the body stays put however the bus lurches.
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not pinned in the head
这些单词我总是记不住。
zhèxiē dāncí wǒ zǒngshì jì bu zhù
These words just won't stick for me.
A word you just learned failing to stick to the wall of your head and sliding off.
记下来 pins it onto paper; 记住 pins it inside your head.
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a way blocked shut
大门被雪堵住了。
dàmén bèi xuě dǔ zhù le
The front gate is blocked by snow.
Snow piled against the front gate so the gate stays fixed and will not swing.
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a feeling that slips the grip
我实在忍不住笑了。
wǒ shízài rěn bu zhù xiào le
I really couldn't help laughing.
A laugh leaking out between the fingers clamped over your mouth.
All of it in one picture
住 is one picture: something in motion caught and pinned where it is. Feet pinned means stopping; a hand pinned to the rail means you stay on your feet. A word that will not pin inside your head is a word you cannot memorise; a gate pinned shut by snow will not open; a laugh that slips the grip is one you could not hold in. So 住 always carries the feel of catching and fixing in place, and 不住 the feel of it getting away from you.