In casual English, can has quietly swallowed may: "Can I leave early?" is now perfectly normal for asking permission. Dutch never made that merger. It keeps two distinct verbs with two distinct jobs: kunnen is about being able (ability and possibility), and mogen is about being allowed (permission and prohibition). When you ask permission, the natural, polite, correct Dutch verb is mogen — Mag ik...? Using Kan ik...? for permission isn't a disaster, but it lands a little oddly, as if you were asking whether it's physically possible rather than whether it's permitted.
The core decision
Ask what kind of "can" you mean:
- Am I / are you ABLE to do it? (skill, capacity, possibility) → kunnen.
- Am I / are you ALLOWED to do it? (rules, permission, parental consent) → mogen.
The deep logic: kunnen is rooted in capability — it answers is this within someone's power or within the realm of the possible? Mogen is rooted in permission — it answers do the rules, or the person in charge, allow this? English merged them under one word, so English speakers have to consciously re-split a concept their language fused.
Mogen: permission and being allowed
Mogen covers the whole territory of permission: asking for it, granting it, and — crucially — denying it. The standard, polite way to ask for something in Dutch is Mag ik...?
Mag ik naar buiten, mama?
May I go outside, mum?
Mag ik je iets vragen?
May I ask you something?
Je mag mijn auto wel lenen, hoor.
You're welcome to borrow my car, you know.
This is also how you order or request in a shop or café — Mag ik een koffie? ("Could I have a coffee?") is everyday and polite. The verb frames it as "am I permitted this," which is exactly the deferential tone you want.
Mag ik afrekenen? Ik heb een beetje haast.
Could I pay? I'm in a bit of a hurry.
Mogen niet: prohibition
The negative side of permission — being forbidden — also belongs to mogen. Je mag niet is the standard way to say "you're not allowed to," and it's the natural translation of English "you can't" when "can't" means "aren't permitted."
Je mag hier niet roken.
You're not allowed to smoke here.
Kinderen mogen niet alleen in het zwembad.
Children aren't allowed in the pool alone.
Sorry, daar mag je niet parkeren.
Sorry, you're not allowed to park there.
Notice the contrast with the previous page: mag niet = forbidden (no permission), which is different again from hoeft niet = no obligation. Dutch keeps "forbidden," "not required," and "not able" in three separate boxes.
Kunnen: ability and possibility
Kunnen (can, to be able) is about capacity and feasibility — skills you have, things that are physically or practically possible.
Ik kan al sinds mijn vierde zwemmen.
I've been able to swim since I was four.
Kun je dit raam openmaken? Het is hier snikheet.
Can you open this window? It's boiling in here.
Dat kan niet waar zijn!
That can't be true! (possibility, not permission)
That last example is pure possibility — nothing to do with permission — and it's solidly kunnen territory.
The overlap: kunnen in polite requests
Here's the nuance that keeps this from being a clean wall. When you ask someone else to do something, kunnen is perfectly natural and polite, because you're literally asking about their ability/willingness to help: Kun je me even helpen? This is not the same as asking permission for yourself.
Kun je me even helpen met deze tas?
Can you help me with this bag for a sec? (asking another person — ability/willingness)
Kunt u dat misschien herhalen?
Could you repeat that, perhaps? (polite request, formal 'u')
So the split is subtle but consistent: when I want permission to do something, I use Mag ik...?; when I ask you to do something for me, Kun je...? is the friendly choice.
Mag ik even langs? — Ja hoor, kun je dat doosje aangeven?
May I get past? — Sure, can you pass me that little box?
Quick-decision table
| You mean… | Verb | Example |
|---|---|---|
| I'm allowed / asking permission | mogen | Mag ik naar de wc? |
| requesting something politely (a coffee, a moment) | mogen | Mag ik een koffie? |
| it's forbidden | mogen niet | Je mag hier niet roken. |
| ability / skill | kunnen | Ik kan zwemmen. |
| possibility / feasibility | kunnen | Dat kan niet. |
| asking another person to do something | kunnen | Kun je me helpen? |
A note on conjugation
Mogen is irregular in the singular: ik mag, jij mag, hij mag — note the g without an extra ending, never ik mog. The plural is regular: wij mogen. Kunnen gives ik kan, jij kunt/kan, hij kan, wij kunnen; for the polite u you'll hear both u kunt and u kan, with u kunt slightly more formal.
Mag ik vanavond bij Sophie blijven slapen?
Can I sleep over at Sophie's tonight? (a child asking — permission → mogen)
Ik kan vanavond niet, ik moet werken.
I can't tonight, I have to work. (possibility → kunnen)
Common Mistakes
❌ Kan ik naar de wc?
Odd for permission — this asks about your physical ability. For permission, use 'mogen'.
✅ Mag ik naar de wc?
May I go to the toilet?
❌ Ik mag heel goed koken.
Incorrect — cooking well is an ability, not a permission. Use 'kunnen'.
✅ Ik kan heel goed koken.
I can cook really well.
❌ Je kan hier niet roken.
Acceptable in loose speech, but for a rule/prohibition Dutch prefers 'mogen niet'.
✅ Je mag hier niet roken.
You're not allowed to smoke here.
❌ Ik mog niet komen.
Incorrect conjugation — the form is 'ik mag', never 'ik mog'.
✅ Ik mag niet komen.
I'm not allowed to come.
❌ Mag jij me even helpen?
Odd — asking another person to help is about their ability/willingness, so 'kunnen' fits better.
✅ Kun jij me even helpen?
Can you help me for a sec?
Key Takeaways
- mogen = permission and prohibition (allowed / not allowed) — and the polite way to ask or request: Mag ik...?
- kunnen = ability and possibility (able / feasible).
- English fused can and may; Dutch keeps them apart — re-split the concept before you speak.
- Subtle overlap: ask permission for yourself with Mag ik...?, but ask another person to act with Kun je...?
- Watch the conjugation: ik mag, never ik mog.
Now practice Dutch
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Dutch→Related Topics
- Modal Verbs: OverviewA2 — A map of the six Dutch modals — kunnen, mogen, moeten, willen, zullen, hoeven — and the one pattern they share: modal + bare infinitive at the end of the clause.
- Moeten vs Hoeven: Must and the Negative of MustB1 — A decision guide for obligation in Dutch — moeten for positive obligation (I have to), hoeven for its negative counterpart (I don't have to), and the crucial trap that 'moet niet' means must NOT while 'hoeft niet' means doesn't HAVE to.
- Zullen vs Gaan: Expressing the FutureB1 — A decision guide for the Dutch future — gaan for intentions and plans ('going to'), zullen for predictions, promises and proposals ('will/shall', 'Zullen we?'), and the present tense for scheduled events — plus why overusing zullen is the classic English-speaker error.
- Kunnen, Weten, Kennen: Can and KnowB1 — Three Dutch verbs sit where English has 'can' and 'know': kunnen = to be able / have the skill (including speaking a language), weten = to know a fact, kennen = to be acquainted with. This page gives one decision rule for all three, dismantles the famous 'Ik kan Frans' language trap, and fixes the errors English speakers make most.