怎麼了grammar point · tier 1 · 怎麼了 — what's the matter / what happened
Fixed question probing the cause behind a noticed change or off condition in someone or something: what's the matter, what happened.
字源 FORM what the parts do
怎 carries the heart (心) underneath that does the wondering, with 乍 lent for a sound ground down to zěn. 麼 is on loan for sound only, worn down to a light me; neither the thread (幺) nor 麻 spells anything here. 了 sits at the end marking that a condition has shifted into one that did not hold before. Together they wonder after the cause of the change.
故事 STORY a scene to remember it by
Someone calm a breath ago has turned strange, and the heart leaps straight to what has come over them.
字源記憶法
框 · Frame
[topic（人/事）]，怎麼了？ （怎麼了 stands alone after the thing it asks about; 了 marks the change it reacts to）
觸 · Trigger
You notice someone or something is now off or different from before, and you ask what has come over it.
序 · The move
1Name the person or thing whose state has shifted, as the topic in front.Is there a change or off-state to react to, not a plain fact you already know the reason for?
2Set 怎麼了 after it, as the whole question; 了 carries the shift.Did 了 stay on, so it reads "what happened" and not the bare manner "how"?
3Read it back as wondering at the cause of the difference.Would the answer report what went wrong or changed, rather than a reason for a fact already stated?
例 · Examples
1李明華Li Minghua (name)今天today沒來didn't come上班to work，他he怎麼了what's the matter / what happened？
Li Minghua didn't come to work today — what's the matter with him?
怎麼了 reacts to a noticed change and asks what has come over it; 為什麼 asks the reason behind a fact already stated. Reach for 怎麼了 when something is off, 為什麼 when you want the cause of a known thing.
怎麼了 with 了 asks what happened — the cause of a change; 怎麼 without 了 asks the manner or means, how something is done. The 了 switches it from "how" to "what's wrong."
怎麼了 asks after a state that has changed; 什麼 alone asks for a thing in the object slot. Swap by whether the answer is a situation or an object.
✗ 你為什麼了？（為什麼 cannot take 了 to ask what's wrong）→ ✓ 你怎麼了？
✗ 他怎麼？（dropping 了 leaves a bare "how," not "what happened"）→ ✓ 他怎麼了？
✗ 你什麼了？（thing-word where you mean the changed state）→ ✓ 你怎麼了？
English splits this into "what's wrong?" and "what happened?" with "what," so learners reach for 什麼; Chinese carries it on 怎 (how) plus 了 (a change has set in). The 了 is not past tense here — it marks the shift the question reacts to.