Dormir flips from o to ue in many present forms, then shifts to u in third-person preterite forms, while keeping regular endings in most other tenses.
Dormir means “to sleep,” and you’ll run into it early in Spanish. It shows up in daily routines, travel plans, and small talk. The catch is that it changes its vowel in the stem, so the form you want depends on the tense and the person.
This page gives you the full set without drowning you in grammar talk. You’ll learn the two stem changes, the forms people say most, and a few drills that make the patterns feel automatic.
What Dormir Means In Real Spanish
In most situations, dormir is just “to sleep.” You’ll hear it with time phrases, routines, and polite questions.
- Sleep:Duermo ocho horas. (I sleep eight hours.)
- Spend the night:Dormimos en un hotel. (We stayed overnight in a hotel.)
- Figurative “sit unused”:El plan duerme en un cajón. (The plan is sitting in a drawer.)
If you only learn one habit, make it this: link each form to a simple English idea in your head (“I sleep,” “I slept,” “I’m sleeping”). That keeps you from freezing mid-sentence.
Spanish Conjugation of Dormir With The Two Stem Changes
Dormir is a stem-changing -ir verb. That means the vowel inside the stem changes in certain slots. With dormir, you’ll see two changes depending on the tense:
O To Ue In Many Present-Time Forms
In the present indicative, the o in dorm- turns into ue in most persons. The two exceptions are nosotros and vosotros.
Present indicative
- yo: duermo
- tú: duermes
- él/ella/usted: duerme
- nosotros/nosotras: dormimos
- vosotros/vosotras: dormís
- ellos/ellas/ustedes: duermen
Quick self-check: if the form starts with duer-, you’re in the right lane.
O To U In Third-Person Preterite
In the preterite, the vowel change is different. Only the third-person singular and plural switch to u. Everything else stays regular.
Preterite
- yo: dormí
- tú: dormiste
- él/ella/usted: durmió
- nosotros/nosotras: dormimos
- vosotros/vosotras: dormisteis
- ellos/ellas/ustedes: durmieron
A lot of learners mix up durmió and dormió. If it’s third person in the preterite, go with u.
Imperfect Stays Regular
The imperfect is plain and steady. No stem change.
Imperfect
- yo: dormía
- tú: dormías
- él/ella/usted: dormía
- nosotros/nosotras: dormíamos
- vosotros/vosotras: dormíais
- ellos/ellas/ustedes: dormían
Use the imperfect for background habits: Cuando era niño, dormía tarde.
Gerund And Participle You’ll Say Often
The gerund is durmiendo. The past participle is dormido. These two show up in common “helper verb” patterns.
- Progressive:Estoy durmiendo. (I’m sleeping.)
- Perfect:He dormido poco. (I’ve slept little.)
Now that you’ve seen the moving parts, add two habits that keep your speaking clean: say the stress clearly, and pick the tense with a simple timeline.
Pronunciation And Stress Notes
Most present forms start with duer-. Say it as one syllable with a glide, closer to “dwehr” than “doo-er.” If you split it into two syllables, it sounds off and slows you down.
Preterite forms carry accent marks that tell you where the stress lands: dormí stresses the last syllable, and durmió stresses the last syllable too. When you write, keep the accent marks; they lock the sound in place.
- duermo → stress on duer
- dormimos → stress on mi
- durmieron → stress near the end, with u in the stem
When you practice aloud, slow down on the stem vowel first. Once the stem feels steady, add the ending.
Choosing Between Present, Preterite, And Imperfect
Dormir shows up in stories, so you’ll often switch between “what happened” and “what was going on.” The preterite points to a finished night or a clear moment. The imperfect paints a habit or a background scene.
Try this trio with the same idea:
- Present:Duermo temprano. (Routine.)
- Preterite:Dormí temprano ayer. (One finished day.)
- Imperfect:Dormía temprano cuando era niño. (Past habit.)
Once you link each tense to a simple timeline, the stem change becomes the easy part.
Where The Stem Changes Show Up Across Tenses
This table is a map. Use it when you’re unsure which vowel you need. It saves time and keeps your sentences smooth.
| Tense Or Mood | Stem Pattern | What To Watch |
|---|---|---|
| Present indicative | o → ue (except nosotros/vosotros) | duermo, duermes, duerme, duermen |
| Present subjunctive | o → ue (except nosotros/vosotros) | duerma, duermas, duerman |
| Preterite (third person) | o → u (only él/ella/ellos/ellas) | durmió, durmieron |
| Imperfect | regular dorm- | dormía, dormíamos |
| The -ré tense (“will” meaning) | regular dormir- | dormiré, dormiremos |
| Conditional | regular dormir- | dormiría, dormirían |
| Progressive (estar + gerund) | uses durmiendo | Stem change lives inside the gerund |
| Perfect tenses (haber + participle) | uses dormido | No stem change in the participle |
| Affirmative commands | present-style stem change | duerme (tú), duerman (ustedes) |
| Negative commands | subjunctive forms | no duermas, no duerman |
Subjunctive Forms And Commands With Dormir
The subjunctive can feel like a wall at first. With dormir, the good news is that the same o → ue change returns in the slots you already know from the present.
Present Subjunctive
Use it after phrases like quiero que, espero que, and es necesario que. If you want to skip labels, think “someone wants or needs something to happen.”
- yo: duerma
- tú: duermas
- él/ella/usted: duerma
- nosotros/nosotras: durmamos
- vosotros/vosotras: durmáis
- ellos/ellas/ustedes: duerman
Sample: Quiero que duermas bien.
Imperfect Subjunctive
You’ll see two common sets. Both are accepted. Pick one set and stick with it while you build speed.
- -ra set:durmiera, durmieras, durmiera, durmiéramos, durmierais, durmieran
- -se set:durmiese, durmieses, durmiese, durmiésemos, durmieseis, durmiesen
Commands
Commands borrow forms you already have.
- Affirmative tú:duerme
- Affirmative usted:duerma
- Affirmative vosotros:dormid
- Affirmative ustedes:duerman
- Negative tú:no duermas
- Negative ustedes:no duerman
If you’re unsure, go to the present subjunctive for negative commands. It works cleanly.
The -ré Tense And Conditional With Dormir
These two are a relief because the stem stays stable: dormir- plus endings. No o → ue, no o → u.
The -ré Tense
Use this tense for “will” ideas. Attach the endings to the whole infinitive: dormiré, dormirás, dormirá, dormiremos, dormiréis, dormirán.
Conditional
Use it for “would” ideas: dormiría, dormirías, dormiría, dormiríamos, dormiríais, dormirían. If you can build one, you can build them all.
Dormirse: “To Fall Asleep” In Everyday Speech
Spanish often uses the reflexive dormirse for “to fall asleep.” The stem-change rules stay the same; you just add the reflexive pronoun.
- Me duermo a las once. (I fall asleep at eleven.)
- Se durmió en clase. (He/She fell asleep in class.)
- Nos dormimos tarde. (We fell asleep late.)
Watch the preterite third person again: se durmió, se durmieron.
Cheat Sheet: High-Frequency Dormir Lines
If your goal is fluency, this table earns its spot. These are the phrases people reach for in real conversations.
| English Idea | Spanish Form | When You’d Use It |
|---|---|---|
| I sleep (habit) | Duermo | Routines, schedules |
| You sleep (habit) | Duermes | Asking someone about their sleep |
| He/She sleeps | Duerme | Talking about a person or a baby |
| We sleep | Dormimos | Trips, shared plans |
| I slept (completed) | Dormí | One finished night |
| He/She slept | Durmió | Preterite third person |
| I was sleeping | Estaba durmiendo | Background action |
| I’ve slept | He dormido | Life experience or recent time |
| Sleep! (tú) | Duerme | Direct command |
| Don’t sleep! (tú) | No duermas | Negative command |
Practice Drills That Build Speed
You don’t need long study sessions to lock in dormir. You need clean reps. Try these quick drills and say the forms out loud.
Drill 1: The Four Anchor Forms
Say these four forms until they roll off your tongue. They carry the pattern:
- duermo
- dormimos
- durmió
- durmiendo
Drill 2: Swap The Subject
Start with Duermo ocho horas. Now swap only the subject and adjust the verb:
- Tú duermes ocho horas.
- Él duerme ocho horas.
- Nosotros dormimos ocho horas.
- Ellos duermen ocho horas.
Drill 3: One Sentence, Three Tenses
Pick one sentence and run it through three time frames:
- Habit: Duermo poco entre semana.
- Completed: Dormí poco anoche.
- Background: Estaba durmiendo cuando llamaste.
Drill 4: Mini Role Play
Ask and answer out loud. Keep your pace steady and let the stem change happen without pausing. Do it twice: once slow, once at normal speed.
- A: ¿A qué hora te duermes?
- B: Me duermo a las once. Anoche me dormí tarde.
- A: ¿Y tu hermano?
- B: Se durmió en el sofá.
Common Errors And How To Fix Them Fast
Most mistakes with dormir come from mixing the two stem changes. Use these quick fixes.
Mixing Up Duermo And Dormo
If you mean “I sleep,” it’s duermo. Save dormo for Portuguese.
Using Dormió Instead Of Durmió
In the preterite, third person takes u: durmió, durmieron. If you can spot “he/she/they” in your sentence, this one fixes itself.
Forgetting Durmamos In The Subjunctive
Nosotros in the present subjunctive is durmamos, not duermamos. That’s a classic trap because the other persons carry ue.
Overusing Estar Durmiendo
English likes “I’m sleeping” for habits. Spanish often prefers the simple present: Duermo mal. Use estoy durmiendo for an action happening right now.
Sources And Further Reading
Conjugations and usage notes here were checked against reference sources that list standard forms and meanings.
- RAE Dictionary Entry: dormir
- WordReference Conjugator: dormir
- Collins Spanish Verb Table: dormir
- StudySpanish Lesson On O→UE Stem Changes
- SpanishDict Conjugation Page: dormir
Final Check Before You Move On
If you can say duermo, duermes, durmió, durmieron, durmiendo, and dormido without thinking, you’ve got the core of dormir. From there, the rest is endings and rhythm.