eldast ("to age, to grow old") is a middle-voice (miðmynd) verb of the inchoative type — it describes a process that happens to its subject, "becoming old," with no external agent. It is built not on a verb but on the adjective family gamall / eldri / elstur ("old / older / oldest"): the comparative stem eld- ("more old") plus the -st gives "grow toward old." That etymology explains both its meaning and its forms. The trap on this page is not the paradigm but a false friend: the identically-spelled active verb elda means "to cook" (ég eldaði kvöldmat "I cooked dinner"), and it has nothing to do with ageing. Same four letters, two unrelated verbs — and getting them crossed produces sentences that range from confusing to comic. This page gives the full -st paradigm and keeps the eldast / elda pair sharply apart.
Conjugation
Type: middle (miðmynd), inchoative; weak (-ti preterite, with assimilation). Auxiliary: hafa — ég hef elst "I have aged." No object: eldast is intransitive — you can't "age" something; the subject simply grows old. The present singular collapses to eldist for all three persons.
| Principal parts | |
|---|---|
| Infinitive | að eldast |
| 1sg present | eldist |
| 1sg past | eltist |
| 3pl past | eltust |
| Supine | elst |
| Person | Present (nútíð) | Past (þátíð) |
|---|---|---|
| ég | eldist | eltist |
| þú | eldist | eltist |
| hann / hún / það | eldist | eltist |
| við | eldumst | eltumst |
| þið | eldist | eltust |
| þeir / þær / þau | eldast | eltust |
| Person | Present subjunctive | Past subjunctive |
|---|---|---|
| ég | eldist | eltist |
| þú | eldist | eltist |
| hann / hún / það | eldist | eltist |
| við | eldumst | eltumst |
| þið | eldist | eltust |
| þeir / þær / þau | eldist | eltust |
| Non-finite & imperative | |
|---|---|
| Imperative (þú) | (not used — one doesn't command someone to age) |
| Imperative (þið) | (not used) |
| Supine | elst |
| Past participle (n) | elst (e.g. vel elst "well-aged") |
What eldast means: a process, not an action
eldast is inchoative — it names the gradual change of state "become old," the way roðna means "go red (blush)" or batna means "get better." The subject is the one undergoing the change; there is no agent doing anything to it. This is the natural home of the middle voice: the -st strips away any external doer and leaves a subject that simply ends up in a new state over time. So amma er að eldast is "Grandma is getting on / ageing," a process unfolding, not an action she performs.
Because it is about how someone or something ages, eldast pairs constantly with adverbs of manner: eldast vel ("age well"), eldast illa ("age badly"), eldast hratt ("age fast"). It applies to people, but also to wine, cheese, buildings, ideas and films — anything that changes with time.
Pabbi er farinn að eldast, hann heyrir ekki eins vel og áður.
Dad's starting to get on in years — he doesn't hear as well as he used to. Infinitive 'eldast' after 'farinn að' (started to).
Þessi mynd hefur elst ótrúlega vel, hún gæti verið frá í gær.
This film has aged incredibly well — it could be from yesterday. Supine 'elst' (perfect with hefur).
Við eldumst öll, það þýðir ekkert að berjast við það.
We all grow old — there's no point fighting it. Present plural 'eldumst'.
The preterite: eltist, eltust
The past tense is where the spelling shifts. The verb is weak, so the past is formed with a dental suffix — but the stem-final d plus the suffix t assimilate to -lt-. The result is eltist (singular) and eltust (plural): hún eltist mikið síðasta árið ("she aged a lot this past year"), þau eltust öll á sama tíma ("they all aged at the same time"). The supine reduces the same cluster to elst (ég hef elst). Keep the present d and the past t straight: present eldist, past eltist.
Hún eltist um mörg ár á þessum erfiðu mánuðum.
She aged years in those hard months. Past singular 'eltist'.
Vínið eltist í eikartunnum í tólf ár.
The wine aged in oak barrels for twelve years. Past singular 'eltist', subject 'vínið'.
The dangerous false friend: eldast (age) vs elda (cook)
Here is the one thing that can genuinely go wrong. elda — same root letters — is a completely separate, common verb meaning "to cook." It is a regular weak verb of the -aði class:
| eldast (age) | elda (cook) | |
|---|---|---|
| Meaning | grow old | cook (food) |
| Voice | middle (-st) | active |
| Object | none (intransitive) | accusative (elda mat) |
| 1sg present | ég eldist | ég elda |
| 1sg past | ég eltist | ég eldaði |
| Supine | elst | eldað |
The -st is the giveaway: if the verb ends in -st (eldist, eltist, eldast), it is ageing; if it is the bare active form with an object (elda mat, eldaði kvöldmat), it is cooking. The danger is the past tense and the perfect: ég eldaði ("I cooked") versus ég eltist ("I aged") — totally different words, but a learner reaching for "I aged" who writes \ég eldaði has just said "I cooked." And note that **elda has no -st middle in the ageing sense* — you cannot "cook yourself old." Two verbs, one spelling: let the -st and the object decide which you mean.
Ég eldaði fisk í gær, en í kvöld nenni ég ekki að elda neitt.
I cooked fish yesterday, but tonight I can't be bothered to cook anything. Both are 'elda' = COOK (eldaði, elda) — not ageing.
Maður eldist hraðar þegar maður sefur illa.
You age faster when you sleep badly. 'eldist' = AGE (the -st form), nothing to do with cooking.
Common Mistakes
❌ Ég eldaði mikið á síðasta ári (meaning 'I aged a lot').
Wrong verb — 'eldaði' is the past of elda = COOK. To say you aged a lot, use the -st verb: 'ég eltist mikið'.
✅ Ég eltist mikið á síðasta ári.
I aged a lot this past year. Past of eldast = 'eltist'.
❌ Hún eldist hratt síðasta sumar.
Incorrect for the past — 'eldist' is the PRESENT; the past tense is 'eltist' (d → t).
✅ Hún eltist hratt síðasta sumar.
She aged fast last summer. Past 'eltist'.
❌ Þau eldust öll mikið þetta árið.
Incorrect — the past PLURAL is 'eltust' (with t), not '*eldust' (that keeps the present-tense d).
✅ Þau eltust öll mikið þetta árið.
They all aged a lot this year. Past plural 'eltust'.
❌ Osturinn hefur eldst vel.
Incorrect — the supine reduces the cluster to 'elst', not '*eldst'.
✅ Osturinn hefur elst vel.
The cheese has aged well. Supine 'elst'.
❌ Amma er að eldast matinn.
Incorrect — 'eldast' (age) takes no object; if you mean Grandma is COOKING the food, that's the active 'elda': 'amma er að elda matinn'.
✅ Amma er að elda matinn.
Grandma is cooking the food. Active 'elda' + accusative 'matinn'. (For 'Grandma is ageing': amma er að eldast — no object.)
Key Takeaways
- eldist / eltist / eltust / elst — a middle-voice inchoative meaning "grow old," built on the eld- stem of gamall / eldri / elstur.
- The past shifts the consonant: present eldist → past eltist / eltust (d + t → lt); supine elst.
- It is intransitive (no object) and pairs with manner adverbs: eldast vel / illa / hratt; applies to people, wine, films, anything that changes with time.
- False friend: elda = "cook" (active, -aði: elda mat, eldaði, eldað). The -st and the presence of an object tell the two apart. "I aged" = eltist; "I cooked" = eldaði.
- Auxiliary is hafa: ég hef elst.
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