als or wenn: Talking About the Past
English has one word for when; German splits it in two. Learn to use als for a single past event or period and wenn for repeated events and everything in the present or future.
Two German words for when
English uses "when" for everything: when I was a child, when I visit my grandma, when the film started. German insists on a choice between two words — als and wenn — and picking the wrong one is one of the most recognisable learner mistakes, so it pays to sort the rule out early.
The short version: als points at one single time in the past — one event, or one closed period. wenn covers everything else — repeated events at any time, and anything in the present or future.
Both are subordinating conjunctions, so nothing new happens to the word order: comma, conjunction, verb at the end of the clause, and the clause-first pattern from the wenn lesson works for als too. The whole lesson is about the choice, not the grammar around it.
Als ich ein Kind war, hatte ich einen Hund.
When I was a child, I had a dog.
Wenn ich meine Oma besuche, backen wir zusammen.
When I visit my grandma, we bake together.
A repeated event in the present — that is wenn territory.
Als wir in Berlin waren, war das Wetter schlecht.
When we were in Berlin, the weather was bad.
als: one single time in the past
Use als when you look back at something that happened once. That can be a short moment — Als der Film angefangen hat, war das Kino voll — or a long stretch of time, as long as it is one closed chapter: Als ich ein Kind war covers years, but it is still a single period of your life that came and went once.
Inside an als-clause you will naturally use the past forms you already own: war and hatte for states, the Perfekt for events, and the past modals where they fit. The conjugated verb goes to the end, exactly as with weil, dass and wenn.
A test that works well: can you put "back then, that one time" in front of the English sentence? When I arrived in Munich — back then, that one time — it was raining. If yes, German wants als.
Als der Film angefangen hat, war das Kino voll.
When the film started, the cinema was full.
One single event, told with the Perfekt inside the als-clause.
Als ich in München angekommen bin, hat es geregnet.
When I arrived in Munich, it was raining.
Als er zwanzig war, ist er nach Hamburg gezogen.
When he was twenty, he moved to Hamburg.
A single life event — the classic als situation.
wenn: repeated past, present and future
wenn keeps the jobs it had in the last lesson — conditions and whenever-events in the present — and adds one more: repeated events in the past. If something happened again and again, German uses wenn even though the sentence is about the past, and usually adds immer to make the repetition audible: Immer wenn wir am Meer waren, haben wir Fisch gegessen.
Put the same sentence with als next to it and the meaning shifts: Als wir am Meer waren, haben wir Fisch gegessen now describes one single seaside holiday. Same words, different conjunction, different story — this minimal pair is the heart of the lesson and worth reading aloud twice.
And for the future, the rule is simple and absolute: als is impossible. Wenn ich morgen Zeit habe, rufe ich dich an. Anything that has not happened yet takes wenn, no exceptions.
Immer wenn wir am Meer waren, haben wir Fisch gegessen.
Whenever we were at the seaside, we ate fish.
Repeated past events take wenn, usually with immer.
Als wir am Meer waren, haben wir Fisch gegessen.
When we were at the seaside, we ate fish.
The same sentence with als — now it is one single holiday.
Wenn ich morgen Zeit habe, rufe ich dich an.
If I have time tomorrow, I will call you.
Future time always takes wenn, never als.
Telling your story: früher und heute
The als/wenn choice comes alive when you talk about your own life — a favourite A2 exam topic and a natural conversation with new friends. Milestones take als: Als ich achtzehn war ... Als ich meine Frau kennengelernt habe ... Als wir umgezogen sind ... Each one happened once, so each one gets als.
Habits, then and now, take wenn. For childhood routines, combine wenn with the past modals: repeated rules of your early life. For today, plain present-tense wenn sentences describe your current routines: Heute koche ich, wenn ich Zeit habe.
Build a five-sentence life story as practice: two milestones with als, one childhood rule with a past modal, and two present habits with wenn. If every single event has als and every repeated one has wenn, you have mastered a distinction that trips up learners well beyond A2.
Als ich klein war, durfte ich nicht lange fernsehen.
When I was little, I was not allowed to watch television for long.
Als ich meine Frau kennengelernt habe, habe ich in Bonn gewohnt.
When I met my wife, I was living in Bonn.
Als wir umgezogen sind, war alles neu für uns.
When we moved, everything was new for us.
Heute koche ich, wenn ich Zeit habe.
These days I cook when I have time.
Check yourself
Quick checks on this lesson. Get at least three quarters right to mark it as completed.
Fill in the gap
ich ein Kind war, hatte ich einen Hund.
Hint: Childhood is one single closed period in the past.
Practise what you learned