Icelandic spreads the work that English packs into "may," "can," "shall," and "will" across four distinct modals — mega, kunna, skulu, and munu — and each carries a sharper, more specific meaning than its loose English counterpart. Mega is permission ("be allowed"). Kunna is acquired skill (and, in one frozen idiom, "might"). Skulu is commitment or command — a speaker promising or ordering, not a neutral future. Munu is detached prediction ("will," often formal). The trap for English speakers is that "shall" and "will" have flattened in English into near-synonyms, while Icelandic keeps skulu (the speaker's own resolve) and munu (a neutral forecast) firmly apart. (This page covers these four; geta "can" has its own page, and vilja "want" is on the vilja/langa page. All four here are preterite-present verbs, so their present singular takes no personal ending — ég má, not ég mái.)
The four modals at a glance
| Modal | Present (ég / þú / hann) | Preterite | Core meaning |
|---|---|---|---|
| mega | má / mátt / má | mátti | be allowed / may (permission) |
| kunna | kann / kannt / kann | kunni | know how to (skill); 'might' in kann að vera |
| skulu | skal / skalt / skal | skyldi | shall (commitment / command) |
| munu | mun / munt / mun | myndi / mundi | will (neutral prediction) |
Note the 2nd-person singular -t endings (mátt, kannt, skalt, munt) — the signature of preterite-present verbs — and the irregular preterites. Munu's preterite myndi is the very "would" auxiliary you meet in conditionals.
mega — permission: 'be allowed / may'
Mega is about permission: whether something is allowed, by rules, by a person, by circumstance. It takes a bare infinitive (no að): þú mátt fara "you may/can go." Asking má ég…? or má maður…? is the standard way to request permission. The negative má ekki is strong — it means "must not / not allowed," a prohibition, not just "doesn't have to."
Máttu reykja hér?
Are you allowed to smoke here? (mega = permission; bare infinitive 'reykja')
Þú mátt alveg fá þér meira, það er nóg til.
You're absolutely welcome to have more, there's plenty. (granting permission)
Maður má ekki leggja hérna — það er bannað.
You're not allowed to park here — it's forbidden. (má ekki = prohibition)
kunna — skill, and the idiom 'might'
Kunna is the learned-skill modal — a competence you've acquired and keep: a language, an instrument, swimming, a recipe. It takes an infinitive with að: ég kann að synda "I know how to swim." (With a bare noun it means "know": hún kann frönsku "she knows French.") This skill sense is fully developed on the geta vs kunna page; here, note the second life of kunna: the frozen idiom kann að vera "it may be / maybe," and X kann að… "X might…," expressing possibility.
Hún kann frönsku og smá ítölsku.
She knows French and a little Italian. (kunna + bare noun = 'know' a skill/language)
Ég kann að synda, en ég er ryðguð.
I know how to swim, but I'm rusty. (kunna + að-infinitive = acquired skill)
Það kann að vera að hann sé þegar farinn.
It may be that he's already left. (kann að vera = 'maybe / it may be')
Þetta kann að hljóma undarlega, en það virkar.
This might sound strange, but it works. (kann að… = 'might', possibility)
skulu — commitment and command
This is the modal English speakers most underestimate. Skulu (present skal) is not a neutral future. It carries the speaker's will: in the 1st person it is a promise / firm resolve ("I shall, I will, I commit to"); in the 2nd person it is a directive / command ("you shall, you are to"). It takes a bare infinitive: ég skal hjálpa þér, þú skalt fara. Because it injects the speaker's authority, skal sounds stronger and more committed than learners expect — it is performative, doing something (promising, ordering), not merely forecasting.
Ég skal hjálpa þér með þetta, engar áhyggjur.
I'll help you with this, don't worry. (1st-person skal = a personal commitment/promise)
Ég skal redda þessu, treystu mér.
I'll sort this out, trust me. (a promise — 'ég skal' is the going-to-bat 'I will')
Þú skalt fara núna — ég meina það.
You're to go now — I mean it. (2nd-person skal = directive/command)
Þið skuluð klára heimavinnuna áður en þið horfið á sjónvarp.
You're to finish your homework before you watch TV. (skuluð — 2pl directive)
munu — neutral prediction: 'will'
Munu (present mun) is the detached, neutral future — a prediction about how things will go, with no commitment or command attached. It belongs to formal and written register (news, forecasts, planning); in casual speech Icelanders more often use the plain present or ætla að for the future. It takes a bare infinitive: það mun rigna "it will rain." Compare skulu: munu forecasts, skulu commits.
Það mun rigna í allan dag samkvæmt spánni.
It's going to rain all day according to the forecast. (munu — a neutral prediction; formal)
Verðbólgan mun líklega lækka á næsta ári.
Inflation will probably fall next year. (munu — detached forecast; academic/journalistic register)
Þetta mun allt reddast, sérðu til.
It'll all work out, you'll see. (munu — predicting an outcome, not promising it)
skulu vs munu: the core contrast
| skulu (skal) | munu (mun) | |
|---|---|---|
| 1st person | promise / resolve — ég skal gera það ("I'll see to it") | prediction — ég mun gera það ("I will do it" — forecast) |
| 2nd person | command — þú skalt fara ("you are to go") | prediction — þú munt sjá ("you'll see") |
| Force | speaker's will / authority | neutral, detached |
| Register | everyday, emphatic | formal / written |
The dividing question: is the speaker putting their will behind it (a promise, an order → skulu) or merely forecasting what will happen (→ munu)? Mixing them changes the speech act: ég skal hjálpa offers help and binds you to it; ég mun hjálpa coolly predicts that helping will occur.
Why this is a stretch for English speakers
English once distinguished "shall" (1st-person commitment, 2nd-person command — "you shall go") from "will" (neutral future), but the two have collapsed: today "I'll help" and "I will help" are read as plain future, and "shall" survives mainly in legal text and offers ("Shall I…?"). So English speakers arrive with the skulu/munu distinction already erased and tend to treat both as bare future, missing the performative punch of skal. The second slip is treating kunna as situational ability (that's geta) and forgetting its "might" idiom (kann að vera). The fixes: feel skal as "I commit / you must", mun as a cool forecast, má as permission, and kann as a skill (with kann að vera = "maybe").
Common Mistakes
❌ Ég kann að koma seinna í kvöld.
Wrong modal for circumstance — 'kunna' is a skill or 'might-possibility', not situational ability. For 'I can come later': ég get komið.
✅ Ég get komið aðeins seinna í kvöld.
I can come a bit later tonight.
Situational ability is geta (+ supine). Kunna is a learned skill (kann að synda) or the "might" idiom (kann að vera) — not "be able to in this situation."
❌ Ég mun hjálpa þér, treystu mér.
Mismatched force — a personal promise uses skulu, not the detached munu: ég skal hjálpa þér.
✅ Ég skal hjálpa þér, treystu mér.
I'll help you, trust me.
A heartfelt promise needs skal (speaker's commitment). Mun would make it a cool prediction that helping will occur — wrong for reassurance.
❌ Þú must ekki reykja hér.
Non-form / wrong verb — for permission use mega: þú mátt ekki reykja hér ('you're not allowed to').
✅ Þú mátt ekki reykja hér.
You're not allowed to smoke here.
Permission and prohibition run through mega. Its 2sg is mátt, and mátt ekki = "must not / forbidden."
❌ Ég skal frönsku.
Wrong modal — knowing a language is kunna, not skulu: ég kann frönsku.
✅ Ég kann frönsku.
I know French.
Competence in a language is kunna (+ bare noun or að-infinitive), never skulu.
❌ Þú skal fara núna.
Agreement error — the 2nd-person singular is 'skalt', not 'skal': þú skalt fara.
✅ Þú skalt fara núna.
You're to go now.
Preterite-present verbs take -t in the 2sg: skalt, mátt, kannt, munt. Skal is the 1st/3rd-person form.
Key Takeaways
- mega (má / mátt / má; pret. mátti) = permission — þú mátt fara; má ég…? requests it; má ekki = prohibition. Bare infinitive.
- kunna (kann / kannt / kann; pret. kunni) = learned skill (kann að synda, kann frönsku) and the idiom kann að vera "maybe / it may be." Skill takes að-infinitive.
- skulu (skal / skalt / skal; pret. skyldi) = commitment (1st person, a promise: ég skal hjálpa) or command (2nd person: þú skalt fara) — the speaker's will. Bare infinitive; stronger than learners expect.
- munu (mun / munt / mun; pret. myndi/mundi) = neutral prediction, "will" — það mun rigna — mostly formal/written.
- skulu vs munu: skal puts the speaker's will behind it (promise/order); mun coolly forecasts. Don't swap them.
- kunna vs geta: kunna = a skill or "might"; geta = situational ability. Ég kann að synda (I know how) vs ég get synt (I'm able to right now).
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Start learning Icelandic→Related Topics
- Modal Verbs: OverviewA2 — The Icelandic modal verbs — geta, vilja, mega, skulu, munu, kunna (bare infinitive) versus eiga að, þurfa að, verða að (with að) — including the crucial fact that geta governs the supine, not the infinitive: ég get gert það, not *get gera.
- geta: 'can/be able' (+ Supine)B1 — The chief Icelandic ability modal geta — present get/getur/getum, preterite gat/gátu, subjunctive gæti — and its single defining quirk: unlike every other modal in the language, geta governs a SUPINE, not an infinitive (ég get talað íslensku, not *ég get tala). Covers ability, inability with ekki, the past 'could', and the polite gæti.
- Expressing the Future: munu, ætla, presentB1 — How Icelandic expresses future time despite having no inflected future tense — the bare present plus a time adverb as the default, munu + infinitive for predictions, ætla að + infinitive for intention, and verða að for obligation-tinged futures, with the munu / ætla / skulu split that carves up English 'will'.
- munu vs skulu vs ætla: Future and IntentionB2 — English 'will / shall / going to' splits across three Icelandic verbs. munu makes a neutral PREDICTION ('it will rain', formal future); skulu expresses the speaker's COMMITMENT — a promise in the 1st person, a command in the 2nd ('I'll definitely help', 'you shall go'); ætla að states an INTENTION or plan ('I'm going to study tonight'). The key is that skal is performative — saying it commits you — a force English 'shall' has mostly lost, so ég skal is stronger than 'I will', and munu is a forecast, never a plan. Includes a decision table.
- megaB1 — Full conjugation of the preterite-present verb mega 'may / be allowed' (má / mátti / máttu / mátt), with its bare-infinitive complement (þú mátt fara), the all-important prohibition mega ekki 'must not' (NOT 'needn't'), the polite past subjunctive mætti ('might I…?'), and the contrast with verða að 'have to'. The one fact learners most need: má ekki is a ban, not the absence of an obligation.
- kunnaB1 — Full conjugation of the preterite-present verb kunna 'know how / can (skill)' (kann / kunni / kunnu / kunnað), covering the two complement patterns — kunna + að-infinitive for a learned skill (kunna að synda) and kunna + bare accusative for known content (kunna ljóðið, kunna íslensku) — plus the idiom kann að vera 'maybe' and the clean split from geta (circumstantial 'can') and vita (factual 'know').