grammar → 太…了
TSUMUGU · TBCL 2 (est.) · 語法
太…了 grammar point · tier 1 · 太…了 excess (too + stative verb)
· tài … le
Marks a quality as past the acceptable limit, with 了 closing the verdict.

字源 FORM what the parts do

太 is 大, a person with arms spread, plus one mark (丶) added: one step past big. The stative verb names the quality being pushed past its limit. 了 sits at the end and shuts the verdict.

故事 STORY a scene to remember it by

The cup fills past its rim and the liquid runs over the side; 了 is the lid pressed down on the spill.
字源自撰記憶法
框 · Frame
太 [stative verb] 了
觸 · Trigger
A quality has gone past what you'll accept, and you want to say so.
序 · The move
1Name the quality as a stative verb (貴, 忙, 大).Is it a quality you can be 'too much' of, not an action?
2Put 太 in front and 了 at the end.Both brackets present? Bare 太 without 了 sounds clipped.
3Confirm it means past the limit, not merely high.If it's high but fine, use 很, not 太…了.
例 · Examples
1這家飯店too / past the limitexpensivecloses the verdict,我不要住。
This hotel is too expensive; I don't want to stay.
界 · Boundary
太…了 is past the acceptable mark and carries a verdict (it's a problem); 很 is high on the scale and neutral (no overflow, no complaint).
太 (no 了)
Spoken 太…了 keeps 了 to close the verdict; 太貴 alone reads as a bare modifier, not the finished judgment.
這家飯店很貴了 ✗ → 這家飯店太貴了 ✓ (了 caps 太, not 很)
太貴,我不要住 ✗ → 太貴了,我不要住 ✓ (keep the closing 了)
我太喜歡 ✗ → 我太喜歡了 ✓ (close it with 了)
English 'too' fits anywhere with no closer, so learners drop the 了; and 'too' and 'very' blur, so 太 gets used where 很 belongs.