What is the Difference between "als", "wenn" and "wann" in German?

Updated: Sep 16

There are a few subordinate clause conjunctions that students find difficult to use, but the conjunctions "als" and "wenn" are widely considered to be particularly confusing and often confused with the question word "wann". While all three might be translated as 'when' into English, they’re used completely differently. Getting them right is crucial for conveying the correct meaning in conversations and writing. In this blog post, I will explain the grammatical differences between them and how they need to be used.

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Understanding the Difference between als vs. wenn

"Als" is used for completed actions and hence in the past, whereas "wenn" is used for recurring events, irrespective of the tense, so when something happens repeatedly or habitually or in conditional sentences. That is, when something happens under a specific condition (similar to "if" in English).

Let's look at some examples, beginning with "als".

Als ich ein Kind war, wohnte ich in Deutschland.

(When I was a child, I lived in Germany)

Ich verließ das Haus, als es anfing zu regnen.

(I left the house, when it started to rain)

Als ich gestern nach Hause kam, war es schon dunkel.

(When I came home yesterday, it was already dark.)

So "als" is the English "when" but only for a specific moment in the past. Let's look at "wenn" now. To reiterate, "wenn" is used primarily in two situations:

Conditional sentences

Repeated events in the past or present

Examples:

Conditional:
- Wenn es regnet, bleibe ich zu Hause.
  (If it rains, I stay at home.)
- Wenn du dein Deutsch verbessern möchtest, musst du regelmäßig üben.
  (If you want to improve your German, you have to practice regularly)
Repeated events:
- Wenn ich Zeit habe, gehe ich joggen.
  (When I have time, I go jogging.)
- Wenn ich morgens aufstehe, gehe ich zuerst ins Badezimmer.
  (Whenever I get up in the morning, I first go to the bathroom)

As you can see, "wenn" is best translated as "if" or "whenever". That is because in all examples, "wenn" describes conditions and situations that can happen multiple times.

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Often, teachers say that "wenn" cannot be used in the past. This is incorrect. The main usage of "wenn" in the past is in the German subjunctive (Konjunktiv 2).

Wenn ich früher mehr Vokabeln gelernt gelernt hätte, wäre mein Griechisch heute besser.

(If I had studied more vocabulary earlier, my Greek would be better today)

So what about wann?

For English native speakers who try to translate the English "when" into German, there is another word that confuses matters further and that is the word "wann". However, "wann" can, in fact, only be used in questions and is therefore quite different from the subordinate clause conjunctions "als" and "wenn".

Wann – Direct and Indirect Questions

"Wann" is used when asking questions about time, both in direct questions (e.g., "When will you arrive?") and indirect questions (e.g., "I don’t know when he will arrive"). It is not used for conditions or repeated events.

Examples:

Direct question:

Wann kommst du nach Hause?

(When are you coming home?)

Wann beginnt dein Deutschunterricht?
(When does your German lesson begin?)

Indirect question:

Ich weiß nicht, wann er ankommt.
(I don’t know when he will arrive.)
Ich frage mich, wann dein Deutschunterricht beginnt.
(I wonder when your German lesson begins)

"Wann" directly inquires about the time something happens or will happen. And since it's a question word, the conjugated verb must be second in German. However, "wann" can also be used in indirect questions which subordinate, i.e. send the conjugated verb to the end. Grammatically, it is still a question word, though, whereas "als" and "wenn" are not.

Key Differences Recap:

Wenn: Used for conditional statements and repeated events.
Als: Used for single events in the past.
Wann: Used in questions about time.

Understanding the differences between "wenn," "als," and "wann" is essential for mastering German. Each word has a specific context in which it is used, and mixing them up can lead to confusion or misunderstandings. By practising with examples and keeping these rules in mind, you'll be able to use each one correctly and confidently. Since practice makes perfect, we have developed some exercises on the German words als, Wenn, and Wann for you.

One final note on "als" in German. It is a confusing word because it also comes up in different grammatical contexts. Check out my blog post on the topic to avoid confusion. Since "als" is used in the past, you might want to brush up on your Perfekt tense, Präteritum and Plusquamperfekt rules in German and revise the three past tenses in the language.