Learn Hardcore German: Ich gehe nicht ins Bett, ohne das Fenster zu schließen. - I do not go to bed without closing the window.

This contraction is very common in spoken and written German when in is followed by das (neuter singular). You will hear ins Bett, ins Kino, ins Auto, etc.

You can say in das Bett, but it sounds more formal or emphatic and is less common in everyday speech. In most normal contexts, ins Bett is the default choice.

Why is it ins Bett (accusative) and not im Bett (dative) here?

The preposition in is a so‑called two-way preposition (Wechselpräposition). With these, the case depends on the meaning:

Accusative → movement into something (direction)
Dative → location in something (no movement)

In your sentence:

Ich gehe ins Bett – you are moving into the bed → accusative
Compare: Ich liege im Bett. – you are already lying in the bed, no movement → dative

So ins Bett (accusative) is correct because it describes movement toward a place (going to bed).

Why is nicht placed before ins Bett and not at the very end of the sentence?

Nicht usually comes:

before the element being negated, or
at the end of the verb phrase, if you’re negating the whole predicate.

In Ich gehe nicht ins Bett, ..., the negation is about the whole action gehe ins Bett. The natural position is:

Ich gehe nicht ins Bett → “I do not go to bed ...”

You would not put nicht at the very end:

✗ Ich gehe ins Bett, ohne das Fenster zu schließen nicht. (wrong)

The infinitive clause ohne das Fenster zu schließen is not what is being directly negated; it’s part of a condition (ohne = without). The main negation targets the main clause action gehe ins Bett, so nicht belongs right before ins Bett.

There is nicht and ohne in the same sentence. Is this a double negation? Does it mean I do close the window?

Yes, logically this is like a double negation, and its effect is similar to English:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.
≈ “I don’t go to bed without closing the window.”

The meaning is:
→ Every time I go to bed, I close the window first.
→ I never go to bed with the window still open.

So although nicht and ohne are both negative in form, together they express a strong positive habit: closing the window is something you always do before going to bed.

What exactly is the ohne … zu schließen construction? How does it work?

This is an infinitive clause with zu introduced by ohne:

ohne
- [accusative object, etc.] + zu
  - infinitive

Structure in your sentence:

ohne
das Fenster (object)
zu schließen (infinitive with zu)

Function: it expresses “without doing X” when the subject of both actions is the same:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.
→ “I don’t go to bed without closing the window (myself).”

If the subject of the second action were different, you would normally use ohne dass + finite clause, e.g.:

Ich gehe nicht ins Bett, ohne dass jemand anderes das Fenster schließt.
“I don’t go to bed without someone else closing the window.”

Why is zu schließen at the end, and why is zu directly in front of schließen?

In German, infinitive clauses form a “zu + infinitive” block that normally goes to the end of its clause:

… das Fenster zu schließen
… nach Hause zu gehen
… Deutsch zu lernen

Rules here:

Zu goes directly before the infinitive verb form (schließen).
The whole block (zu schließen) appears at the end of the infinitive clause, after any objects:
- ohne das Fenster zu schließen
  (not ohne zu schließen das Fenster)

This is a normal German word order pattern: objects (like das Fenster) come before the zu + infinitive block.

Why is it das Fenster? Can this article change?

Fenster is a neuter noun in German:

singular: das Fenster
plural: die Fenster

In your sentence, das Fenster is the direct object of schließen, so it’s in the accusative. For neuter nouns, nominative and accusative are both das in the singular:

Nominative: Das Fenster ist offen.
Accusative: Ich schließe das Fenster.

Other possible forms:

Plural: ohne die Fenster zu schließen – “without closing the windows”
Indefinite: ohne ein Fenster zu schließen – “without closing a (single) window”

Could I use zumachen instead of schließen here? How would that work with zu?

Yes, you can also use zumachen (more colloquial) instead of schließen.

But pay attention: zumachen is a separable verb (prefix zu- + machen). In a zu + infinitive structure, the extra zu is inserted between the prefix and the verb:

Base verb: zumachen
Infinitive with zu: zuzumachen

So your clause could be:

ohne das Fenster zuzumachen – “without closing the window”

Similarly:

aufschließen → aufzuschließen
zumachen → zuzumachen

Using schließen vs. zumachen is mostly a register/style choice:
schließen is a bit more neutral/formal; zumachen is more casual.

Why is there a comma before ohne?

In German punctuation rules, you normally put a comma before infinitive clauses introduced by certain words, including um, ohne, statt / anstatt, außer, als.

Here, ohne das Fenster zu schließen is such an infinitive clause, so the comma is mandatory:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.

You might see infinitive clauses without a comma in other patterns, but with “ohne + zu + infinitive” the comma is required.

Can I move ohne das Fenster zu schließen to the beginning of the sentence?

Yes. You can front this clause for emphasis:

Ohne das Fenster zu schließen gehe ich nicht ins Bett.

This is perfectly grammatical and sounds natural. The meaning remains the same; you’re just putting extra focus on the condition:

Original: Neutral order, focus on not going to bed without that action.
Fronted: Stronger emphasis on the condition (closing the window) as the important bit.

Word order recap:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.
Ohne das Fenster zu schließen gehe ich nicht ins Bett.

Does the present tense gehe here mean a general habit?

Yes. German Präsens (present tense) is used not only for actions happening right now, but also very often for:

general habits
- Ich trinke morgens Kaffee. – I (always) drink coffee in the morning.
facts and routines
- Ich fahre jeden Tag zur Arbeit. – I go to work every day.

In your sentence:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.

This naturally reads as a general rule or habit: “I never go to bed without closing the window (first).”

You could also use a future tense (Ich werde nicht ins Bett gehen, ohne …), but that would sound like a specific promise or statement about the future, not a general habit.

What’s the difference between zu schließen and geschlossen zu haben in this kind of sentence?

You sometimes see two forms:

ohne das Fenster zu schließen
ohne das Fenster geschlossen zu haben

Both can be translated “without having closed the window,” but there’s a nuance:

ohne … zu schließen (simple infinitive)
- Neutral, most common form
- Time relationship is usually clear from context: you close (or don’t close) the window before going to bed.
ohne … geschlossen zu haben (perfect infinitive)
- Grammatically stresses that the action would have been completed beforehand
- Sounds more formal, more written, and is used less in everyday speech.

In most everyday contexts, Germans prefer the simple form:

Ich gehe nicht ins Bett, ohne das Fenster zu schließen.
rather than
Ich gehe nicht ins Bett, ohne das Fenster geschlossen zu haben.

The first sentence is idiomatic and completely sufficient to show that closing the window happens before going to bed.