Sign inSign up

geuneun allameul mos deureoseo sueobe jigakhaesseo.

그는 알람을 못 들어서 수업에 지각했어.geuneun allameul mos deureoseo sueobe jigakhaesseo.
He couldn’t hear the alarm, so he was late to class.
Elon.io is an online learning platform
We have an entire course teaching Korean grammar and vocabulary.

Start learning Korean now

Questions & Answers about geuneun allameul mos deureoseo sueobe jigakhaesseo.

What does the ending -어서 in 못 들어서 do here?

-아서/어서 links two clauses with a cause-effect meaning: “because/so.”
So 알람을 못 들어서 = “because (he) couldn’t hear the alarm,” which explains why he was late.

Alternatives and nuance:

  • -니까: more speaker-judgment/justification; fine too: 알람을 못 들으니까 지각했어.
  • -기 때문에: more formal/explicit causation: 알람을 못 들었기 때문에 지각했어.
  • 때문에 (noun): attach to a noun phrase: 알람을 못 들은 것 때문에 지각했어.
Why is it 못 and not 안 들어서?
  • 못 = inability/lack of success (objective impediment). “Couldn’t hear (the alarm).”
  • 안 = non-performance/choice (volitional or simple negation). “Didn’t listen (even though one could).” Here, not hearing an alarm is an inability, so 못 들어서 is natural.
Why is it 들어서 and not 들어서요 or something like that?

The sentence ends with 지각했어, which is casual (no 요). Keeping the clause before it at the same register is natural. If you make it polite, change the whole sentence:

  • Casual: 알람을 못 들어서 수업에 지각했어.
  • Polite: 알람을 못 들어서 수업에 지각했어요.
  • Formal: 알람을 못 들어서 수업에 지각했습니다.
What’s going on with 듣다 → 들어서?

듣다 is a ㄷ-irregular verb. Before a vowel-initial ending like -어서, its ㄷ changes to ㄹ:

  • 듣다 + -어서 → 들어서 (because (I) hear/heard) Other examples:
  • 묻다(ask) → 물어서
  • 걷다(walk) → 걸어서 Note: not all ㄷ-final verbs are irregular (e.g., 받다, 닫다 are regular).
Does 들어서 here mean “entered, so”?

No. It’s from 듣다 “to hear,” not from 들어가다/들어오다 “to enter/come in.”
Context and the object 알람(을) make it “hear” here.

Is 그는 natural in everyday speech?

In casual spoken Korean, explicit pronouns like 그는 are often omitted or replaced:

  • Omit: 알람을 못 들어서 수업에 지각했어. (Context supplies “he/I.”)
  • Use a colloquial pronoun: 걔는 (if referring to “that guy/that friend”). 그는 feels more written or formal; fine in narratives.
What’s the difference between 그는 and 그가?
  • 그는: topic particle 은/는 → “as for him,” sets the topic; often contrastive or backgrounding.
  • 그가: subject particle 이/가 → marks “he” as the grammatical subject, often new or focused information. Both are possible, but 그는 sounds like you’re continuing to talk about “him.”
Why is it 수업에 and not 수업을?

With “being late (to)”, Korean marks the target event with 에:

  • 수업에 지각했어 = “was late to class” Same with workplace/meetings: 회사에 지각하다, 회의에 지각하다.
    You can also say 수업에 늦었어 (using 늦다).
What’s the nuance between 지각하다 and 늦다?
  • 지각하다 (遲刻): “to be late (to a scheduled thing).” Common for school/work; a bit formal.
  • 늦다: general “to be late,” very common and casual.
    Both work: 수업에 지각했어 / 수업에 늦었어. “지각” sounds slightly more institutional.
Is 지각하다 ever the “perception” verb?

There are homophones:

  • 지각(遲刻)하다 = be late (this sentence).
  • 지각(知覺)하다 = perceive (philosophical/academic).
  • 지각(地殻) = Earth’s crust (noun).
    Context tells them apart. Here it’s clearly “tardiness.”
What politeness level is 지각했어?

Casual/informal (no 요).
Other levels:

  • Polite: 지각했어요
  • Formal: 지각했습니다
  • Very casual/plain narrative (diary): 지각했다
Is the spacing correct? Why not “못들어서” or “지각 했어”?
  • 못 들어서: space between 못 (adverb) and the verb. Writing “못들어서” is nonstandard.
  • 지각했어: written together because 지각하다 forms a single verb. “지각 했어” is usually considered a spacing error.
Could I say “알람이 안 울려서” instead?

Yes, different cause:

  • 알람을 못 들어서: He couldn’t hear it (maybe it rang, but he slept through it).
  • 알람이 안 울려서: The alarm didn’t ring.
    Another natural variant: 알람 소리를 못 들어서 (explicit “alarm sound” as the object of 듣다).
Why not “못 들었어서”?

In causal clauses with -아서/어서, Korean usually doesn’t stack the past marker on the subordinate verb unless needed for a special nuance.
So use 못 들어서, not “못 들었어서.” The time sequence is clear without -었-.

How do you pronounce “못 들어서”? It looks tricky.
  • Careful pronunciation (dictionary form): [못 드러서] (RR: mot deureoseo)
  • In natural speech, the ㄷ in 들어- often becomes tense after final consonants, so it can sound like [몯 뜨러서] (“mot tteureoseo”).
    “지각했어” is [지가켇써] (“jigakhaesseo”).
Can I drop some particles in casual speech?

Yes. In informal conversation, you might hear:

  • 알람 못 들어서 수업에 지각했어. (drop 을)
  • 알람 못 들어서 수업 지각했어. (drop 에; still understandable, but keeping 에 is clearer) Particles make it clearer and are preferred in careful speech/writing.
Is “알람” the best word? What about “자명종”?
  • 알람 (loanword): very common, especially for phone alarms.
  • 자명종: traditional alarm clock.
    If you mean the sound, 알람 소리 is explicit: 알람 소리를 못 들어서….
Any other natural ways to say this?
  • 늦잠 자서 수업에 지각했어. (I overslept, so I was late.)
  • 알람을 듣지 못해서 수업에 늦었어. (using -지 못해서)
  • 알람이 안 울려서 수업에 늦었어. (alarm didn’t go off)
Why is the object marker on 알람? Isn’t 듣다 “to listen to (sounds)”?

Korean often uses the sound as the object, but metonymy is common. Both are used:

  • 알람(을) 듣다: “hear the alarm” (device stands for its sound).
  • 알람 소리(를) 듣다: more explicit “hear the alarm sound.”
    In this sentence, 알람을 못 들어서 is idiomatic.