Trennbar oder untrennbar — the prefix that splits, and the one that doesn't
German verbs love prefixes. Some prefixes split off the verb in main clauses and march to the end (aufstehen → ich stehe um sieben auf). Others stay glued to the verb forever (verstehen → ich verstehe das). And a third group — the dual prefixes (durch-, über-, unter-, um-, wider-, wieder-) — can do both, with a meaning shift between the two readings. Three rules tell you which is which: (1) Always separable: an-, ab-, auf-, aus-, bei-, ein-, mit-, nach-, vor-, weg-, zu-, zurück-, zusammen- (and many more) — these have their own clear, locatable meaning ('off', 'up', 'out', 'back'). The verb's stress falls on the prefix: ÁUF-stehen, ÉIN-kaufen. (2) Always inseparable: be-, emp-, ent-, er-, ge-, miss-, ver-, zer- — these have no independent meaning; they only modify a verb. The stress falls on the verb stem, never on the prefix: be-STEH-en, ver-STEH-en, er-KLÄ-ren. (3) Dual: durch-, hinter-, über-, um-, unter-, wider-, wieder- — separable when literal/spatial, inseparable when figurative. Stress is the audible cue: ÚM-ziehen (move house, separable) vs. um-ÁR-men (to embrace, inseparable). Master prefix → master half of German vocabulary.
Separable prefixes — the prefix marches to the end
In a main clause, the prefix detaches from the verb and goes to the end. aufstehen = to get up. Ich stehe um sieben auf. einkaufen = to shop. Sie kauft jeden Tag ein. mitkommen = to come along. Kommst du mit? anrufen = to call. Ich rufe dich später an. The infinitive aufstehen is one word; the conjugated form is two pieces, with everything else of the sentence between them. In subordinate clauses (after weil, dass, wenn) the verb pieces rejoin at the end: … weil ich um sieben aufstehe. In Perfekt, the ge- of the past participle goes BETWEEN prefix and stem: aufgestanden, eingekauft, mitgekommen, angerufen. With zu + infinitive (umzu): zu also goes between: aufzustehen = 'to get up' (in Es ist Zeit aufzustehen.). The stress on a separable verb always lands on the prefix: ÁUF-stehen, ÉIN-kaufen, ÁN-rufen. If you can hear the stress on the prefix, it's separable.
The most useful separable prefixes
Each prefix has a fairly stable meaning that you can carry across many verbs. an- ('on / at / toward'): ankommen (to arrive), anrufen (to call), anziehen (to put on / get dressed), anfangen (to begin). ab- ('off / away / down'): abfahren (to depart), abnehmen (to lose weight / to take off), abholen (to pick up). auf- ('up / open'): aufstehen (to get up), aufmachen (to open), aufhören (to stop). aus- ('out / off'): ausgehen (to go out), ausziehen (to take off / move out), ausschalten (to turn off). ein- ('in / into'): einkaufen (to shop), einsteigen (to get in / board), einladen (to invite). mit- ('with / along'): mitkommen (to come along), mitnehmen (to take along). nach- ('after / behind'): nachdenken (to think over), nachschauen (to check). vor- ('before / fore'): vorhaben (to plan), vorstellen (to introduce). zu- ('to / shut'): zumachen (to close), zuhören (to listen). weg- ('away'): weggehen (to go away). zurück- ('back'): zurückkommen (to come back). Notice: each prefix carries spatial intuition that English usually splits across separate prepositions ('on/up/down/out/in').
Inseparable prefixes — glued forever
be-, emp-, ent-, er-, ge-, miss-, ver-, zer- never split. They never take ge- in the past participle either. verstehen = to understand. Ich verstehe das. Perfekt: Ich habe das verstanden. (no ge-!) bekommen = to receive. Ich habe einen Brief bekommen. erklären = to explain. Sie hat es erklärt. gehören = to belong. Es gehört mir. vergessen = to forget. Ich habe es vergessen. zerstören = to destroy. Der Sturm hat das Haus zerstört. misstrauen = to mistrust. Ich misstraue ihm. empfehlen = to recommend. Was empfiehlst du? Each inseparable prefix shifts the verb's meaning: be- often makes intransitives transitive (antworten ↔ beantworten with direct object); er- often = 'achieve / bring about' (erreichen, erfinden); ver- often = 'away / wrongly / completely' (verlieren, vergessen, verbrennen); zer- = 'apart / to pieces' (zerstören, zerreißen); miss- = 'wrongly / mis-' (missverstehen).
Stress is the audible cue
When you hear a German verb spoken, prefix vs. stem stress tells you instantly which kind it is. Separable → stress on prefix: ÁN-rufen, ÉIN-kaufen, ÁUF-stehen, ÁB-fahren, ÁUS-gehen. Inseparable → stress on stem: be-KÓMM-en, ver-STÉH-en, er-KLÄ́-ren, ge-HÖ́-ren, ent-SCHÉI-den. Train your ear: a separable verb sounds 'punchy' on the first syllable; an inseparable verb sounds 'level' or stem-stressed. This matters most for the dual prefixes below, where stress is the only clue.
Dual prefixes — durch-, über-, unter-, um-, wider-, wieder-
These six can be either separable or inseparable, and the meaning often shifts. The rule of thumb: literal / spatial = separable; figurative / abstract = inseparable. Stress disambiguates. um-: ÚM-ziehen (separable) = to move house (Ich ziehe nächsten Monat um.); um-ÁR-men (inseparable) = to embrace (Ich umarme dich.). ÚM-werfen = to knock over (literal); um-GÉ́-ben = to surround (figurative). über-: Ǘ-ber-setzen (separable, literal) = to ferry across (Der Fährmann setzt uns über.); über-SÉT-zen (inseparable, abstract) = to translate (Ich übersetze den Text.). unter-: ÚN-ter-gehen (separable) = to go down / set / sink (Die Sonne geht unter.); unter-NÉH-men (inseparable) = to undertake (Wir unternehmen viel.). durch-: DÚRCH-fahren (separable, literal) = to drive through (Wir fahren durch.); durch-DÉN-ken (inseparable, figurative) = to think through. wieder-: WÍ-der- is rare separable; wieder-HÓ-len (inseparable) = to repeat (Ich wiederhole das.) — note that WIE-der-sehen ('to see again') is treated as separable. wider- (with -i-, 'against') is typically inseparable: wider-SPRÉ-chen (to contradict). The pattern to remember: when the prefix keeps its concrete spatial sense, it's separable; when the prefix-plus-verb has fused into a new abstract meaning, it's inseparable, and the stress moves to the stem.
Past participle: ge- placement
Separable: ge- sits BETWEEN prefix and stem. aufstehen → aufgestanden. einkaufen → eingekauft. anrufen → angerufen. mitkommen → mitgekommen. Inseparable: NO ge- at all. verstehen → verstanden. bekommen → bekommen. erklären → erklärt. gehören → gehört. vergessen → vergessen. Dual prefixes: follow whichever reading applies — umgezogen (moved house, separable) vs. umarmt (embraced, inseparable). This is why pronouncing the stress correctly when you learn a verb pays off in the past tense too.
Quick decoder
(1) Hear the stress on the first syllable? Separable. The prefix will detach in main clauses and ge- will go between prefix and stem in Perfekt. (2) Hear the stress on the stem? Inseparable. No splitting, no ge- in Perfekt. (3) Looking at one of be-, emp-, ent-, er-, ge-, miss-, ver-, zer-? Always inseparable, no exceptions worth memorizing. (4) Looking at one of an-, ab-, auf-, aus-, bei-, ein-, mit-, nach-, vor-, weg-, zu-, zurück-? Always separable. (5) Looking at durch-, über-, unter-, um-, wider-, wieder-? Check the meaning: literal/spatial → separable; abstract/figurative → inseparable. The stress in a dictionary or audio is the final tiebreaker.
