kunna is the Icelandic verb for a skill you possess — "to know how to, to be able to (because you've learned it)." It is one of the preterite-present verbs, so its present singular has no -r (ég kann, like English I can). The thing that makes it tricky is not its forms but its two complement patterns: kunna + að-infinitive for an ability (kunna að synda "know how to swim"), and kunna + a bare accusative object for memorised content (kunna ljóðið "know the poem [by heart]," kunna íslensku "know Icelandic"). Sort those two from each other — and kunna from geta (situational "can") and vita (factual "know") — and this very common verb falls into place.
Conjugation
Class: preterite-present (present singular has no ending). Complements: að-infinitive (skill) or bare accusative (known content). Auxiliary: hafa — ég hef kunnað "I have known (how to)." Note the u-umlaut/-u throughout the plural and past: kunnum, kunni, kunnu.
| Principal parts | |
|---|---|
| Infinitive | að kunna |
| 1sg present | kann |
| 1sg past | kunni |
| Supine | kunnað |
| Person | Present (nútíð) | Past (þátíð) |
|---|---|---|
| ég | kann | kunni |
| þú | kannt | kunnir |
| hann / hún / það | kann | kunni |
| við | kunnum | kunnum |
| þið | kunnið | kunnuð |
| þeir / þær / þau | kunna | kunnu |
| Person | Present subjunctive | Past subjunctive |
|---|---|---|
| ég | kunni | kynni |
| þú | kunnir | kynnir |
| hann / hún / það | kunni | kynni |
| við | kunnum | kynnum |
| þið | kunnið | kynnuð |
| þeir / þær / þau | kunni | kynnu |
| Non-finite & imperative | |
|---|---|
| Imperative | — (none in use; you can't command "know how") |
| Supine | kunnað |
| Past participle | — (no ordinary verbal-adjective use) |
| Middle voice (miðmynd) | — (none; the lookalike kynnast 'get to know' is a different verb) |
Watch the present singular: ég kann, þú kannt, hann kann — bare kann in 1st/3rd person, -t in 2nd (kannt), never kunnur. The plural has u: kunnum, kunnið, kunna. The past indicative kunni / kunnir / kunni / kunnum / kunnuð / kunnu keeps u; the past subjunctive switches to y: kynni, kynnir, kynni, kynnum, kynnuð, kynnu. Note that present-1sg kunni-look-alikes collide: kunni is also the present subjunctive 1sg, but context makes it clear.
kunna að + infinitive: a learned skill
With an að-infinitive, kunna means "know how to" — a skill acquired by learning, something you carry with you. This is the contrast with geta: kunna að synda "know how to swim (I learned it)" describes a standing competence, regardless of whether you can swim right now.
Hún kann að spila á fiðlu og á píanó.
She can play the violin and the piano. — kunna að = a learned skill she possesses, not a one-off possibility.
Ég kann ekki að skauta, ég datt alltaf sem barn.
I can't skate, I always fell over as a child. — kunna ekki að = lacking the skill. About know-how, not today's circumstances.
Kannt þú að baka súrdeigsbrauð?
Do you know how to bake sourdough? — Kannt þú að …? asks about a skill. Note the 2sg kannt.
kunna + bare accusative: known content
When the object is memorised content — a poem, a song, a language, a phone number, the rules — kunna takes a bare accusative with no preposition and no infinitive: kunna ljóðið "know the poem (by heart)," kunna íslensku "know Icelandic (be able to speak it)," kunna reglurnar "know the rules." This is "know" in the sense of having it down, mastered and ready to produce — which is exactly why a language goes with kunna, not vita.
Ég kann allan textann utan að.
I know all the lyrics by heart. — kunna + accusative (textann) = have it memorised. utan að 'by heart' reinforces it.
Hann kann íslensku reiprennandi eftir tvö ár.
He knows Icelandic fluently after two years. — a language is kunna + accusative, never vita. kunna = command of the language.
kann að vera: "maybe / it may be"
The fixed phrase kann að vera (literally "may be") is an everyday way to say "maybe, possibly." Here kunna slides into epistemic "might," and the construction often stands as a hedge: það kann að vera "that may be so," kann að vera að … "it may be that …."
Það kann að vera rétt hjá þér.
You may well be right. — kann að vera = 'may be'; a soft, common way to concede a point.
Kann að vera að ég komi aðeins seinna.
It may be that I'll come a bit later. — kann að vera að + clause hedges a plan: 'possibly I'll…'.
kunna vs geta vs vita: three "knows/cans"
English "can" and "know" smear across all three. Keep them apart by what each is really about:
| Verb | Is about | Complement | Example |
|---|---|---|---|
| kunna | a learned skill / memorised content | að-inf. or bare accusative | kunna að synda; kunna ljóðið |
| geta | circumstantial ability / possibility now | supine | geta synt (í dag) |
| vita | knowing a fact | clause / bare accusative fact | vita svarið; vita að… |
So ég kann að synda "I know how to swim (skill)" versus ég get synt í dag "I can swim today (it's possible right now)" versus ég veit hvar laugin er "I know where the pool is (a fact)." Note the complement gives them away too: kunna + að-infinitive, geta + supine, vita + a clause or a fact.
Ég kann að keyra en ég get ekki keyrt í kvöld, ég er búinn að drekka.
I know how to drive but I can't drive tonight, I've been drinking. — kunna (skill) vs geta (circumstance), in one sentence. Note geta + supine keyrt.
Common Mistakes
❌ Ég kann ekki að koma í kvöld.
Wrong verb — a one-off impossibility is circumstantial: use geta + supine. kunna is for skills, not tonight's situation.
✅ Ég get ekki komið í kvöld.
I can't come tonight.
Tonight's availability is a circumstance (geta), not a skill (kunna). This is the single most common kunna/geta mix-up.
❌ Hún kannt að dansa.
Agreement error — 2sg is kannt, 3sg is kann. With hún (3sg) it's kann, not kannt.
✅ Hún kann að dansa.
She knows how to dance.
The -t belongs to þú (þú kannt); 1st and 3rd singular are bare kann.
❌ Ég veit íslensku.
Wrong verb — knowing/speaking a language is kunna + accusative, not vita. vita is for facts.
✅ Ég kann íslensku.
I know (speak) Icelandic.
A language you've mastered goes with kunna; vita would mean "know a fact about Icelandic," not "be able to use it."
❌ Ég kann synda.
Missing að — kunna takes an að-infinitive for a skill: kunna að synda, not kunna synda.
✅ Ég kann að synda.
I know how to swim.
Unlike geta (bare supine) and mega/skulu/munu (bare infinitive), the skill sense of kunna keeps the að. (Only the content sense drops it — and there the object is a noun, not a verb.)
Key Takeaways
- kunna / kann / kunni / kunnað — a preterite-present; present singular ég kann has no -r, 2sg þú kannt, plural kunnum / kunnið / kunna.
- kunna að + infinitive = a learned skill (kunna að synda). kunna + bare accusative = memorised content (kunna ljóðið, kunna íslensku).
- kann að vera = "maybe / it may be," a useful epistemic hedge.
- Past indicative kunni (with u); past subjunctive kynni (with y) = "might." Don't confuse kynni with the verb kynnast "get to know."
- Split the trio: kunna = skill/known content, geta (+ supine) = circumstantial ability now, vita = factual knowledge.
Now practice Icelandic
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Icelandic→Related Topics
- geta vs kunna: 'Can' (Ability vs Skill)B1 — Both translate English 'can', but geta is situational ability — being able to do something in the present circumstances (+ SUPINE: ég get komið á morgun) — while kunna is an acquired, learned skill you possess (+ INFINITIVE: ég kann að synda). The same English 'I can swim' splits into kann (I know how) vs get (I'm able to right now), and the supine-vs-infinitive complement is a reliable formal tell.
- vita vs kunna vs þekkja: Three Ways to 'Know'A2 — A decision guide for the three Icelandic verbs that all translate as English 'know' — vita for facts, kunna for skills and memorised content (including languages), and þekkja for being acquainted with a person or place.
- mega, kunna, skulu, munuB1 — Four Icelandic modals beyond geta and vilja: mega 'be allowed/may' (þú mátt fara), kunna 'know how to / might' (ég kann að synda; kann að vera 'maybe'), skulu 'shall — commitment or command' (ég skal hjálpa, þú skalt fara), and munu 'will — neutral prediction' (það mun rigna). The key nuance: skal in the 1st person is a PROMISE and in the 2nd a directive — a performative force English 'shall' has lost — while munu is a detached prediction.
- geta (can / be able)A2 — Full conjugation of the preterite-present verb geta (get / gat / gátu / getað), the all-important rule that it takes a SUPINE not an infinitive (ég get gert það), the subjunctive gæti, and the contrast with kunna ('know how').
- vita (to know a fact)A2 — Full conjugation of the preterite-present verb vita (veit / vissi / vissu / vitað), its 'know-a-fact' semantics versus kunna ('know how') and þekkja ('be acquainted with'), the að-clause complement, the phrases vita af and vita um, and the set phrase að því er ég best veit.