acostarse

Acostarse is one of the first verbs you meet when you start talking about your daily routine. It means to go to bed — to lie down for the night, or sometimes just to lie down. It is a reflexive verb (you always lie yourself down) and a stem-changing verb in the o > ue family, so the stressed o of the stem turns into a diphthong ue in the present indicative, the present subjunctive, and most of the imperative. Two grammatical wrinkles in one verb, both very common — which is why acostarse shows up in nearly every beginner textbook.

Non-finite forms

The reflexive pronoun in the non-finite forms attaches to the end of the infinitive or gerundio (acostarse, acostándose) — and triggers a written accent on the gerundio because the original stress pattern would otherwise shift.

Indicative — simple tenses

Presente

The classic o > ue shift: it happens in every form except nosotros and vosotros, where the stress lands on the ending and the stem stays put.

Pretérito perfecto simple

Stem-changing -ar verbs do not carry the change into the preterite — this is regular -ar, no surprises.

Pretérito imperfecto

Futuro simple

Condicional

Indicative — compound tenses

Compound tenses keep the reflexive pronoun in front of haber — it never attaches to the participle: me he acostado, never he acostadome.

Pretérito perfecto compuesto

Pretérito pluscuamperfecto

Futuro compuesto

Condicional compuesto

Subjunctive — simple tenses

Presente de subjuntivo

Same o > ue pattern as the present indicative — change in the four stressed forms, no change in nosotros and vosotros.

Imperfecto de subjuntivo (-ra / -se)

Built off the ellos-form of the preterite, which is regular here — so neither set carries a stem change.

Both endings are interchangeable in modern Spain; the -ra set dominates everyday speech, while -se is more frequent in literary and formal writing.

Subjunctive — compound tenses

Pretérito perfecto de subjuntivo

Pluscuamperfecto de subjuntivo

Imperative

The peninsular vosotros affirmative is built from the infinitive by replacing -r with -d — but with reflexive verbs the -d drops before the pronoun os: acostaos, not acostados. This is one of the most-missed details of beginner Spanish in Spain.

Note two further details: the nosotros affirmative drops the final -s before -nos (acostémos + nos → acostémonos); and the pronoun attaches as one word in every affirmative form, which forces a written accent to preserve the original stress (acuéstate, acuéstese, acostémonos, acuéstense).

Meanings beyond "to go to bed"

The reflexive acostarse covers a wider range than English "go to bed":

The non-reflexive acostar (transitive) means to lay someone else down — most often a child: Voy a acostar a los niños (I'm going to put the kids to bed). The reflexive is what you use about yourself.

High-frequency phrases in peninsular Spanish

The classic English-speaker error

English uses an active, non-reflexive phrase ("I go to bed") where Spanish uses a reflexive one ("I lay myself down"). The pronoun is not optional. Yo acuesto a las once is wrong — that would mean I put someone (else) to bed at eleven and the listener will wait for a missing object. You must say me acuesto a las once.

A second classic confusion: English speakers reach for ir a la cama (literally "go to the bed") as a translation. That phrase exists but is unusual in Spain for the daily-routine meaning. The natural verb is acostarse (for going to bed for the night) or irse a dormir (to head off to sleep). Irse a la cama tends to suggest sulking or retreating, not the nightly routine.

Common Mistakes

Key Takeaways

• Acostarse is reflexive: the pronouns me, te, se, nos, os, se are mandatory whenever the subject acts on themselves.
• The o > ue stem change appears in the four stressed forms of the present indicative and present subjunctive, plus most imperatives — never in nosotros / vosotros (present) or in the preterite, imperfect, future, or conditional.
• The peninsular vosotros affirmative reflexive is acostaos — the -d drops before os.
• For putting someone else to bed, use the non-reflexive acostar a alguien; for going to bed yourself, always reflexive.
• Common-time idioms (acostarse con las gallinas, acostarse a las tantas, acostarse hecho polvo) sound much more natural than literal translations.