Ændre ('to change, to alter, to modify') is a weak verb with one structural feature that trips up nearly every English speaker: when something changes by itself — the weather, a person, a situation — Danish requires the reflexive ændre sig. The bare verb ændre is transitive; it needs an object. Forgetting the sig in the intransitive sense is the most frequent mistake on this page, closely followed by reaching for ændre when Danish actually wants skifte.
Principal parts
Ændre is weak and regular: past -ede, participle -et. Keep the æ exact in every form.
| Form | Danish | English |
|---|---|---|
| Infinitive | (at) ændre | to change / alter |
| Present | ændrer | change(s) |
| Past | ændrede | changed |
| Past participle | ændret | changed |
| Present perfect | har ændret | have changed |
| Imperative | ændr | change! |
The perfect auxiliary is har in both the transitive and the reflexive use: jeg har ændret planen ('I've changed the plan') and vejret har ændret sig ('the weather has changed'). Even though ændre sig describes a change of state, Danish keeps har here because the construction is reflexive — the sig carries the change, and reflexives take have. You will never see er ændret sig.
Ændre noget — alter something (transitive)
The plain verb takes a direct object: you change something. Use it whenever an agent deliberately modifies a thing.
Vi er nødt til at ændre datoen for mødet.
We have to change the date of the meeting.
Kan du ændre skriftstørrelsen? Den er for lille.
Can you change the font size? It's too small.
Den nye lov ændrer reglerne for udlejning.
The new law changes the rules for renting out property.
Common fixed objects include ændre mening ('change one's mind') and ændre planer ('change plans').
Hun ændrede mening i sidste øjeblik.
She changed her mind at the last moment.
Ændre sig — change (intransitive)
When the subject changes on its own, with no external agent, Danish uses the reflexive ændre sig. English uses the same word "change" for both — I changed the plan and the plan changed — but Danish splits them: transitive ændre, intransitive ændre sig.
Vejret ændrede sig pludseligt.
The weather changed suddenly.
Han har ændret sig meget, siden vi sidst sås.
He's changed a lot since we last met.
Situationen kan nå at ændre sig inden i morgen.
The situation may yet change before tomorrow.
The noun en ændring ('a change, an alteration') comes from the same root: Der er sket en stor ændring i planerne ('A big change has happened in the plans').
Ændre vs. skifte vs. forandre vs. lave om på
Danish has several "change" verbs, and they are not interchangeable. Ændre = alter or modify something while it stays the same entity (you adjust it). Skifte = swap one thing out for another, replace (change trains, change a tyre, change jobs). Forandre = transform more deeply, often used like ændre but with a weightier, sometimes literary ring (Rejsen forandrede hende — 'The journey transformed her'). Lave om på is the colloquial 'redo / rearrange' (informal).
Jeg skal skifte tog i Odense.
I have to change trains in Odense.
Vi har lavet om på hele stuen.
We've rearranged the whole living room.
The key contrast for learners is ændre vs skifte: you ændrer a thing (modify it), but you skifter between things (replace one with another). "Change trains" is skifte tog, never ændre tog, because you are not modifying a train — you are swapping one train for another. The same logic applies to skifte job ('change jobs' — you leave one and take another), skifte ble ('change a nappy'), and skifte mening. That last one is interesting: both ændre mening and skifte mening exist and both mean 'change one's mind', but ændre frames it as adjusting your existing view while skifte frames it as swapping it for the opposite — a subtle nuance native speakers feel rather than think about.
Why English masks the transitive/intransitive split
The deeper reason this verb is hard is that English uses a single labile verb for both jobs. "Change" in English is what linguists call ambitransitive: The committee changed the rules (transitive) and The rules changed (intransitive) use the identical word with no extra marking. Danish refuses this economy. The transitive job goes to bare ændre + object; the intransitive job — where there is no agent, the thing simply becomes different — must carry the reflexive sig. So where English lets one verb stand in two grammatical roles, Danish forces you to choose, and the choice is the sig. Once you internalise that sig is doing the work English does invisibly, the rest follows: any time you could rephrase the English with "become different" rather than "make something different", reach for ændre sig.
Reglerne ændrede sig, uden at nogen sagde det.
The rules changed without anyone saying so.
Udvalget ændrede reglerne uden varsel.
The committee changed the rules without notice.
Common mistakes
❌ Vejret ændrede meget i går.
Incorrect — when something changes by itself, you need the reflexive 'sig'.
✅ Vejret ændrede sig meget i går.
The weather changed a lot yesterday.
❌ Jeg skal ændre tog i Odense.
Incorrect — swapping one train for another is 'skifte', not 'ændre'.
✅ Jeg skal skifte tog i Odense.
I have to change trains in Odense.
❌ Han ændrde planen.
Incorrect — 'ændre' is weak; the past is 'ændrede', not 'ændrde'.
✅ Han ændrede planen.
He changed the plan.
❌ Hun er ændret sig meget.
Incorrect — 'ændre sig' takes 'har', not 'er'.
✅ Hun har ændret sig meget.
She's changed a lot.
❌ Vi ændrer os mødet til fredag.
Incorrect — changing a thing is transitive 'ændre' + object; no 'sig' here.
✅ Vi ændrer mødet til fredag.
We're moving the meeting to Friday.
Key takeaways
- Principal parts: ændre – ændrer – ændrede – har ændret; weak (-ede / -et), auxiliary har (even in the reflexive).
- Transitive ændre
- object = alter something; intransitive needs ændre sig = change by itself (the sig agrees with the subject).
- Skifte = swap/replace one thing for another (skifte tog), not the same as ændre; forandre = transform; lave om på = colloquial 'redo'.
- Keep the æ exact in every form: ændre, ændrede, ændret, ændring.
Now practice Danish
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Start learning Danish→Related Topics
- Skifte, Ændre, Bytte: Three 'Changes'B2 — Danish splits the English verb 'change' into three — skifte (switch one thing for another), ændre (alter something itself), and bytte (exchange or trade). A decision guide with a one-line test.
- SkifteB1 — Full reference for the Danish verb skifte ('to change / switch / swap'), with its principal parts, the key collocations, and how it differs from ændre, forandre and bytte.
- Reflexive VerbsA2 — Inherently reflexive Danish verbs that always need sig/mig/dig — glæde sig, skynde sig, sætte sig, føle sig, gifte sig, more sig, lægge sig — and how they differ from reciprocals.