太/很
tài / hěn
很 is not very — it is a stand that props the adjective up
The picture A gauge with a needle. 很 is only the stand that lets the needle rest somewhere on the dial; 太 is the needle shooting past the red line and taking your feelings with it. To actually turn the dial up to very, reach for 非常, not 很. 很热 is close to plain it's hot; only 非常热 says it's really hot.
Where the picture shows up in 太/很
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just resting on the dial
今天很热。
jīntiān hěn rè
It's hot today.
A needle come to rest somewhere on the dial and just staying there
Say 今天热 without 很 and it sounds like a comparison — hot today, unlike other days. 很 is the prop that stops that.
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past the red line
今天太热了，别出去了。
jīntiān tài rè le, bié chūqu le
It's way too hot today — don't go out.
The needle crossing the red mark, and a hand closing the window and putting the going-out plans away
太 almost always ends with 了.
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the prop under an adjective
这家店的菜很好吃。
zhè jiā diàn de cài hěn hǎochī
The food at this place is good.
An empty plate, chopsticks set down, and a nod
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overflowing in the good direction
太好了，我们六点见！
tài hǎo le, wǒmen liù diǎn jiàn
That's great — see you at six!
Checking the time you agreed on and your fist closing as your shoulders come up
太好了 is not excessively good; it is an exclamation.
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not reaching the line
我不太喜欢这个颜色。
wǒ bú tài xǐhuan zhège yánsè
I'm not really keen on this colour.
A hand hovering over one colour swatch, hesitating, then moving to another
不太 is not very much not; it is a soft not really.
All of it in one picture
It's hot today and the food here is good just stand the needle somewhere on the dial — that is 很. Too hot, don't go out is the needle past the red line, changing what you do, which is 太; and the burst of that's great is 太 as well, over the line in the good direction. The last one, 不太, has the needle failing to reach the line at all: not really. 很 carries almost no weight — it is the prop an adjective needs in order to stand — while 太 is the mark that the line has been crossed.