Lassen — six everyday meanings, one verb
lassen is one of the most common verbs in German and the most ambiguous. It packs at least six distinct uses, all built on the core idea of 'letting something happen / not interfering'. Forms: ich lasse, du lässt, er lässt, wir lassen, ihr lasst, sie lassen; Präteritum ließ; Partizip II gelassen (alone) but the double-infinitive 'lassen' in Perfekt when paired with another verb (just like modals — see L37). The six uses: (1) Permit / let — Lass mich gehen. = Let me go. (2) Have something done / cause — Ich lasse mein Auto reparieren. = I'm having my car repaired. (3) Leave behind — Lass die Tasche hier! = Leave the bag here! (4) Stop / quit / give up — Lass das! = Stop that! (5) Reflexive sich lassen — Das lässt sich machen. = That can be done. sich gehen lassen = to let oneself go. (6) Command 'let's …' (lass uns / lasst uns) — Lass uns gehen! = Let's go! Same verb every time; the meaning falls out of the syntax around it.
Use 1 — permit / let
lassen + Akk + Infinitiv = to let someone do something. Lass mich gehen. = Let me go. Sie lässt die Kinder im Park spielen. = She lets the children play in the park. Ich lasse dich entscheiden. = I'll let you decide. Mein Vater ließ mich nicht ausgehen. = My father didn't let me go out. The person you're letting do something is in the Akkusativ; the action is an infinitive without zu. Negate with nicht: Ich lasse dich nicht gehen. This is the closest to English 'let'.
Use 2 — have something done / cause
Same syntax (lassen + Akk + Infinitiv), but now the subject is having a third party do something. Ich lasse mein Auto reparieren. = I'm having my car repaired (= someone else does the repairing). Er lässt sich die Haare schneiden. = He's getting his hair cut. Sie lässt das Essen kommen. = She's having the food delivered. The 'doer' is unstated; the focus is on what the subject arranges. English uses 'have someone do X' or the causative 'get X done' here. Distinguish from Use 1: in Use 1 you grant permission; in Use 2 you initiate the action without doing it yourself. Context tells you which.
Use 3 — leave behind
lassen + Akk + Ortsangabe (place) = to leave (an object) somewhere. Ich habe meine Schlüssel zu Hause gelassen. = I left my keys at home. Lass die Tasche hier! = Leave the bag here! Lass mich allein! = Leave me alone! Here lassen has no second verb; the place phrase is what completes the meaning. Compare verlassen = to leave (a place / a person, in a deeper sense): Er hat seine Frau verlassen. = He left his wife. lassen = leave a thing somewhere; verlassen = abandon a place or person.
Use 4 — stop / quit / give up
lass das! = stop it! / cut it out! Lass das Rauchen! = Quit smoking! Sie hat das Trinken gelassen. = She gave up drinking. As an imperative, Lass das! is a sharp command equivalent to 'stop that' or 'don't'. With a noun (often a nominalized verb), lassen = to give up the habit. This is a transitive use, no second verb needed. Note also the fixed phrase Lass mal! = 'Don't bother / forget about it' (a friendly waving-off).
Use 5 — sich lassen (reflexive)
Reflexive sich lassen + Infinitiv is a very common German way to express passive possibility ('can be done'). Das lässt sich machen. = That can be done. Die Tür lässt sich nicht öffnen. = The door can't be opened. Das Problem lässt sich leicht lösen. = The problem can easily be solved. This replaces kann + Passiv: Die Tür kann nicht geöffnet werden. = Die Tür lässt sich nicht öffnen. (slightly more idiomatic). Also: sich gehen lassen = to let oneself go (slack off). sich überraschen lassen = to let oneself be surprised. sich nicht beirren lassen = not let oneself be confused. The pattern: subject lets something happen TO itself.
Use 6 — let's (lass uns / lasst uns)
Lass uns + Infinitiv (singular du-form) or Lasst uns + Infinitiv (plural ihr-form) = let's …. Lass uns gehen! = Let's go! Lass uns Pizza bestellen! Lasst uns anfangen! = Let's start (to a group)! Slightly more formal: Wir wollen gehen. or Gehen wir! (a hortative imperative without lassen). The lass uns version is most common in informal speech and feels like a friendly suggestion. NOT to be confused with Use 1 (Lass mich gehen = Let me go), where the addressee is being asked to permit the speaker.
Perfekt — double infinitive (like modals)
When lassen pairs with another verb, the Perfekt uses a double infinitive: Ich habe mein Auto reparieren lassen. = I had my car repaired. Er hat sich die Haare schneiden lassen. = He had his hair cut. Sie hat das Essen kommen lassen. = She had the food delivered. Auxiliary is always haben; lassen stays as an infinitive (NOT gelassen) when there's another infinitive in the clause. Standalone (Uses 3, 4) take the regular Partizip II: Ich habe meine Schlüssel zu Hause gelassen. Sie hat das Rauchen gelassen. In subordinate clauses with the double infinitive, the conjugated haben moves out of final position: … weil ich mein Auto habe reparieren lassen (just like with modals).
Quick decoder
When you see lassen, ask: (1) is there an infinitive after it? If yes → permission (Use 1) or causative (Use 2); decide by who's doing the action. (2) Is it just lassen + object + place? → leaving behind (Use 3). (3) Imperative Lass das! with a noun? → stop / give up (Use 4). (4) Reflexive sich + lassen + Infinitiv? → 'can be done' (Use 5). (5) Lass uns / Lasst uns + Infinitiv? → 'let's …' (Use 6). The English equivalents — let, have done, leave, quit, can be done, let's — are six different verbs. German uses one.
