ALS oder WENN? 🤓 When to use which! | B1+ Level

"Als" and "wenn" both translate to "when" (and sometimes "if"), but German makes a strict distinction between them that English simply doesn't have — and the past tense is where most learners slip up. Here's exactly when to use each one, at every tense.

The Core Difference: One-Time vs. Repeated

The single most important feature to remember: als refers to a single, one-time event, while wenn refers to something repeated or general — habitual actions, general truths, or "whenever" situations. This one distinction decides almost every als-vs-wenn choice you'll ever face.

"Wenn" in the Present Tense

In the present tense, only wenn is used — for both single and repeated events — since German doesn't need the als/wenn distinction here: Wenn ich Zeit habe, gehe ich schwimmen. (When/if I have time, I go swimming.) This can express either a repeated habit or a conditional "if," depending on context.

"Wenn" in the Future Tense

The same rule holds for the future: use wenn, never als, regardless of whether the future event happens once or repeatedly: Wenn ich in Deutschland ankomme, rufe ich dich an. (When I arrive in Germany, I'll call you.) Since the als/wenn split is really about referring back to the past, it simply doesn't apply to the present or future.

"Wenn" vs. "Als" in the Past Tense

This is where the real distinction kicks in. Use als for a single completed event in the past: Als ich 18 war, bin ich nach Berlin gezogen. (When I was 18, I moved to Berlin — a one-time event.) Use wenn for something repeated or habitual in the past: Wenn ich Kind war, habe ich oft im Park gespielt. (When[ever] I was a child, I often played in the park — a repeated situation.) A useful test: if you could add "jedes Mal" (every time) to the sentence and it still makes sense, use wenn; if it describes a single moment, use als.

Important Features to Keep in Mind

Both als and wenn are subordinating conjunctions, so both send the conjugated verb to the end of their clause, just like weil or dass. And remember: this als-vs-wenn distinction only matters in the past — outside the past tense, wenn is always your answer.

Bonus Tip: "Als" Also Means "As" in Other Contexts

Outside of time expressions, als has a completely different, very common use meaning "as" (in the role of): Als Lehrer verdiene ich nicht viel. (As a teacher, I don't earn much.) Don't confuse this "als" (as/in the role of) with the temporal "als" (when) — context makes it clear which one you're dealing with, but it's worth knowing both exist.

Frequently Asked Questions

What's the basic difference between "als" and "wenn"?

"Als" refers to a single, one-time event, while "wenn" refers to something repeated, habitual, or general.

Which one do I use in the present or future tense?

Always "wenn" — the als/wenn distinction only applies in the past tense.

How do I use "als" and "wenn" correctly in the past?

Use "als" for a single completed past event, and "wenn" for something repeated or habitual in the past.

Is there a quick test to choose between them in the past?

Yes — if you could add "jedes Mal" (every time) and the sentence still makes sense, use "wenn"; if it describes one specific moment, use "als."

Does "als" have any other meaning besides "when"?

Yes, "als" also means "as" (in the role of), as in "Als Lehrer verdiene ich nicht viel" (As a teacher, I don't earn much) — a completely separate use from the temporal "als."

Distinctions like als vs. wenn stop being a guessing game once you get real practice — which is exactly what our B1 German Course offers.