Breakdown of Ich weiß nicht, wofür diese Taste am Gerät ist.
Questions & Answers about Ich weiß nicht, wofür diese Taste am Gerät ist.
Because wofür diese Taste am Gerät ist is a subordinate clause (specifically, an embedded / indirect question).
In German:
- In a main clause, the finite verb is in second position:
- Wofür ist diese Taste am Gerät? – direct question
- In a subordinate clause introduced by a conjunction or question word, the finite verb goes to the end:
- … wofür diese Taste am Gerät ist. – embedded question after ich weiß nicht
So the pattern is:
- Ich weiß nicht, wofür diese Taste am Gerät ist.
I don’t know what this button on the device is for.
Wofür literally means “for what”. It replaces für + was and is used in questions (direct or indirect) about purpose or function:
- Wofür ist diese Taste? – What is this button for?
Differences:
wofür
- Standard, neutral, good in both spoken and written German.
- Very common for “What is this (button, tool, key, feature) for?”
wozu
- Also “what for / for what purpose”, but slightly more focused on goal or intended use.
- Often interchangeable with wofür, especially for functions:
- Wozu ist diese Taste? – What’s the function / purpose of this button?
für was
- More colloquial / spoken, less formal.
- Grammatically acceptable, but in standard written German wofür is preferred.
- Ex.: Ich weiß nicht, für was diese Taste ist. (colloquial)
In your sentence, wofür is the most natural and standard choice.
German distinguishes between wissen and kennen more strictly than English distinguishes “to know”.
wissen = to know a fact, information, answer to a question
- Ich weiß nicht, wofür diese Taste ist.
I don’t know what this button is for. (I don’t have that information.)
- Ich weiß nicht, wofür diese Taste ist.
kennen = to be familiar with a person, place, thing, or situation
- Ich kenne diese Taste nicht.
I’m not familiar with this button / I don’t know this button.
- Ich kenne diese Taste nicht.
So in your sentence, you are missing information (the function of the button), not familiarity with the button itself, so wissen is correct.
Ich kenne nicht, wofür diese Taste ist is ungrammatical.
In this construction, you normally do not add es before the clause.
Natural options:
- Ich weiß nicht, wofür diese Taste am Gerät ist. ✅
- Ich weiß es nicht. (by itself) ✅
- Ich weiß nicht, wofür diese Taste am Gerät ist. – and you can optionally drop nicht
- clause and just say Ich weiß es nicht.
But combining both like:
- Ich weiß es nicht, wofür diese Taste am Gerät ist. ❌ (feels wrong / unidiomatic)
Use Ich weiß es nicht when there’s no explicit subordinate clause specifying what you don’t know. When you give the content right after with wofür … ist, you don’t use es.
In German, you must put a comma before a subordinate clause.
- Ich weiß nicht, wofür diese Taste am Gerät ist.
The clause starting with wofür is an indirect question (embedded question), which counts as a subordinate clause. So the comma is mandatory.
Rule: Any clause introduced by a conjunction or a question word (dass, weil, wenn, wann, wo, wie, warum, wofür, etc.) generally requires a comma before it.
Because Taste (button, key) is:
- feminine: die Taste
- In this clause, Taste is the subject of the subordinate clause → nominative.
- Feminine nominative singular for dies- is diese.
So:
- diese Taste = this button (subject, nominative feminine singular)
- dieser Taste = of this button / to this button (genitive or dative feminine)
- dieses would match a neuter or masculine genitive noun, but Taste is feminine, so dieses Taste is incorrect.
am is the contraction of an dem:
- an dem Gerät → am Gerät
Meanings:
- am Gerät = on the device / on this piece of equipment, but with a sense of “attached to / located on / part of the housing of” the device.
It’s like saying “on the device itself” (its surface, casing, front panel, etc.).
Why not auf dem Gerät?
- auf dem Gerät literally suggests something lying on top of the device (e.g., “There’s a book on the device”). That’s a different spatial relation.
- For buttons, controls, labels, displays, etc. that are designed as part of the device, German naturally uses am Gerät.
So diese Taste am Gerät ≈ “this button on the device / this button on the unit/front panel.”
Yes.
- Ich weiß nicht, wofür diese Taste am Gerät ist.
Emphasizes this specific button on the device. - Ich weiß nicht, wofür diese Taste ist.
Also correct and natural; the context will usually make it clear that the button is on some device.
You add am Gerät if you want to be more specific (e.g., there are several devices, or you’re distinguishing this button from others elsewhere).
You can, but the meaning changes.
Ich weiß nicht, wofür diese Taste am Gerät ist.
= “I don’t know what this button is for / what its function is.”Ich weiß nicht, was diese Taste am Gerät ist.
Literally: “I don’t know what this button is (supposed to be).”
This sounds like you don’t even recognize that it is a button, or maybe you’re not sure whether it’s a button, a light, a sensor, etc.
So for “I don’t know what this button does / what it’s for,” use wofür (or also wozu):
- Ich weiß nicht, wofür / wozu diese Taste am Gerät ist.
In Ich weiß nicht, wofür diese Taste am Gerät ist, nicht is negating the verb wissen (“to know”), not the button or the function.
Basic pattern:
- Ich weiß. – I know.
- Ich weiß nicht. – I don’t know.
When you then add what you don’t know (with a subordinate clause), nicht stays next to weiß:
- Ich weiß nicht, wofür diese Taste am Gerät ist.
If you moved nicht to the end:
- Ich weiß, wofür diese Taste am Gerät ist nicht. ❌
that would be wrong; it doesn’t fit German word order and would be interpreted oddly (and still incorrect) as negating the function, not the knowing.
So: negate the main verb where it appears; keep the subordinate clause intact.
No, it’s not a relative clause; it’s an indirect question / embedded question.
A relative clause would describe a noun and usually uses der, die, das, welcher, etc.:
- die Taste, die am Gerät ist – the button that is on the device
Your clause expresses the content of what you don’t know (like “what this button is for”), so it’s an indirect question:
- Ich weiß nicht, wofür diese Taste am Gerät ist.
The question word wofür is the clue: it introduces an interrogative content, not a relative description.
Yes, they refer to slightly different types of controls:
die Taste
- Typically a flat or low-profile button, like on a keyboard, remote control, calculator, touch panel.
- Often something you press quickly and it returns to its position.
der Knopf
- More like a knob or button-shaped object you can press or turn.
- Can mean clothing button too.
- On devices, Knopf is common in everyday speech for any physical button.
der Schalter
- A switch, usually for on/off or toggling states.
- Often something that stays in its new position until you switch it back.
In many casual contexts, Germans might say Knopf for a physical button, but Taste is very natural when talking about buttons on devices, especially if they’re flat, electronic-style buttons (like on a remote or control panel).
Yes, that is also correct:
- Ich weiß nicht, wozu diese Taste am Gerät ist. ✅
Nuance:
- wofür – what it is for, what it is used for, its function
- wozu – what purpose / goal it serves; also often used for “what’s the point of …?”
In practice, for device functions, wofür and wozu are largely interchangeable, and both sound natural. Some speakers have a slight preference, but both are fine in standard German.