Bitte lass das Fenster offen.

the window

Breakdown of Bitte lass das Fenster offen.

• bitte: please
• offen: open
• lassen: to leave

Questions & Answers about Bitte lass das Fenster offen.

What verb form is lass, and why not lasse/lässt/lassen?

Lass is the second-person singular imperative of lassen (“to let/leave”). The imperative for du drops the pronoun and usually the ending.

• Present (for orientation): ich lasse, du lässt, er/sie/es lässt, wir lassen, ihr lasst
• Imperatives: du lass!, ihr lasst!, Sie lassen Sie!

Why is du missing?

Imperatives normally omit the subject pronoun. You could add du for emphasis or contrast (Lass du das Fenster offen.), but the neutral request is simply Lass ….

How would I say this formally or to more than one person?

• Formal (Sie): Bitte lassen Sie das Fenster offen.
• Plural (ihr): Bitte lasst das Fenster offen. Same meaning; just different levels of formality or number.

What does Bitte do, and where can it go?

Bitte softens the command into a polite request. It’s flexible in position:

• Bitte, lass das Fenster offen.
• Lass bitte das Fenster offen.
• Lass das Fenster offen, bitte. All are natural; initial Bitte feels slightly more courteous.

Why is offen at the end?

With lassen, the pattern is: verb + object + predicate (state). So: lass + das Fenster + offen. Other examples: Lass die Tür zu., Lass das Licht an.

Why offen and not offene?

Here offen is a predicative adjective (a state), so it does not take an ending. Attributive adjectives (before a noun) do: das offene Fenster, but Das Fenster ist offen / Lass das Fenster offen.

Is offen the same as auf here?

Both are used with windows/doors to mean “open.” Offen (adjective) is neutral and widely used; auf (adverb) is very common in speech: Lass das Fenster auf. In writing, offen lassen is the safest. You’ll also see auf lassen (two words); the fused verb auflassen exists but is less common.

Can I use geöffnet instead of offen?

You can, but for windows it sounds formal/technical. Geöffnet is common for businesses and official notices (Das Geschäft ist geöffnet). For everyday speech about windows, prefer offen (or auf).

What case is das Fenster, and how can I tell?

Accusative (direct object of lassen). For neuter nouns the article is the same in nominative and accusative (das), so it looks identical. With a feminine noun you’d still see die: Lass die Tür offen.

How do I say the negative: “Don’t leave the window open”?

Bitte lass das Fenster nicht offen. Another natural option is to phrase the desired action: Mach das Fenster zu, bitte.

How do I talk about the past: “I left the window open”?

Ich habe das Fenster offen gelassen. The participle is gelassen (not “gelässt”). Example: Er hat das Fenster die ganze Nacht offen gelassen.

Is lassen separable? How is it different from verlassen?

Lassen is not separable. It means “to let/allow/leave (in a state).” Verlassen means “to leave/abandon” (depart from) and can’t mean “let.” Compare: Lass das Fenster offen. vs. Er hat das Haus verlassen.

Why is it spelled with ss and not ß?

After a short vowel, German uses ss: lassen, lass. After a long vowel/diphthong, you’ll see ß: preterite ließ (“left/let”). Example: Er ließ das Fenster offen.

Can I replace das Fenster with a pronoun?

Yes: Lass es bitte offen. If the referent is clear from context, es is the natural choice for a known neuter noun like das Fenster.

Are there softer or more indirect ways to ask?

Yes:

• Kannst du bitte das Fenster offen lassen?
• Würden Sie das Fenster bitte offen lassen? (very polite) Modal particles can soften it further: Lass doch mal das Fenster offen.

Does this mean “keep it open” or “open it now”?

It means “ensure it stays open” (don’t close it). If you want someone to open it now, say Mach bitte das Fenster auf or Öffne bitte das Fenster.