German verbs conjugate for person and number in the present tense, and then reach for one of two past-tense strategies depending on whether you're speaking or writing. Most of the system is regular enough to learn as a set of endings; the parts that aren't regular — stem changes, irregular participles, the choice between two auxiliary verbs — are exactly the parts worth spending deliberate time on, because they're also the parts you'll use constantly.
Präsens: the regular endings
Regular ("weak") verbs in the present tense drop the -en (or -n) from the infinitive and add a person-specific ending to the stem. Take machen (to make/do), stem mach-:
| Person | Ending | Form |
|---|---|---|
| ich | -e | mache |
| du | -st | machst |
| er/sie/es | -t | macht |
| wir | -en | machen |
| ihr | -t | macht |
| sie/Sie | -en | machen |
That six-slot pattern — -e, -st, -t, -en, -t, -en — is the backbone of the entire present tense, and it applies to the overwhelming majority of German verbs without modification. A stem ending in -d, -t, or certain consonant clusters (öffnen, arbeiten) inserts an -e- before the ending purely for pronunciation — du arbeitest, not du arbeitst — but the underlying pattern is the same six endings.
Stem-changing verbs
A specific group of strong verbs changes its stem vowel in the du and er/sie/es forms only — the rest of the conjugation stays regular. This matters because it's easy to assume a verb is irregular throughout when actually only two of its six forms differ from the pattern above.
Three vowel shifts cover most of these verbs:
- a → ä: fahren (to drive) → du fährst, er/sie/es fährt. Wir fahren, ihr fahrt, sie fahren stay regular.
- e → i: geben (to give) → du gibst, er/sie/es gibt.
- e → ie: sehen (to see) → du siehst, er/sie/es sieht.
There's no rule that predicts which verbs shift and which don't from the infinitive alone — fahren shifts, sagen doesn't, and both look like ordinary -en verbs on the page. This is memorized per verb, which is one reason a ranked list like the 100 most common German verbs is worth working through directly rather than trying to derive conjugations from spelling patterns.
Perfekt: haben or sein, plus Partizip II
The Perfekt is German's default past tense in speech: a conversation about yesterday, last week, or last year in spoken German almost always uses Perfekt rather than Präteritum, even though English speakers instinctively reach for the simple past. Perfekt is built from an auxiliary verb (haben or sein), conjugated for person, plus the Partizip II (past participle) of the main verb, which stays unchanged regardless of person: ich habe gemacht, du hast gemacht, er hat gemacht — the participle doesn't move.
Forming the Partizip II. Weak (regular) verbs form it as ge- + stem + -t: machen → gemacht, spielen → gespielt, kaufen → gekauft. Strong (irregular) verbs form it as ge- + stem (often changed) + -en: gehen → gegangen, sehen → gesehen, sprechen → gesprochen. The strong pattern is the one worth memorizing case by case, since the stem itself often shifts in ways that aren't predictable from the infinitive — trinken → getrunken, not getrinkt or getrunkt.
Verbs already carrying an inseparable prefix (be-, ge-, er-, ver-, zer-, ent-, emp-, miss-) or ending in -ieren skip the ge- entirely: besuchen → besucht, verstehen → verstanden, studieren → studiert. The separable verbs guide covers what happens to the ge- when the verb has a separable prefix instead — it doesn't disappear, it moves into the middle of the word.
Which auxiliary? This is the choice that actually needs a rule, because guessing wrong is a common and noticeable mistake. Sein is used for:
- Verbs of motion from one place to another: gehen (to go), fahren (to drive), fliegen (to fly), laufen (to run).
- Verbs of change of state: aufwachen (to wake up), sterben (to die), werden (to become), wachsen (to grow).
- A short list of exceptions that don't fit either pattern but are used constantly: sein itself, bleiben (to stay), passieren (to happen).
Every other verb takes haben — which in practice means haben is the default and sein is the marked case you check for. A few verbs take both, depending on how they are used: ich bin nach Berlin gefahren (I travelled there, no object, sein) but ich habe das Auto gefahren (I drove the car, an object, haben). The rule underneath is that the sein reading is the intransitive one describing the movement itself.
Präteritum: the written past
The Präteritum (simple past) is formed differently — weak verbs add -te plus a person ending to the stem (machen → ich machte, du machtest...), strong verbs change the stem vowel again, often to a third distinct form beyond the infinitive and the Partizip II (gehen → ging, sehen → sah, sprechen → sprach).
The usage split is the part worth internalizing, because it's not symmetric with English at all. Written German — narrative prose, news reporting, formal writing — defaults to Präteritum for the past, the way English defaults to simple past. Spoken German defaults to Perfekt instead, to the point that using Präteritum in casual conversation for most verbs can sound slightly stiff or literary.
The one sharp exception: sein, haben, and the modal verbs (können, müssen, dürfen, sollen, wollen, mögen) are Präteritum even in speech. Ich war müde (I was tired), ich hatte keine Zeit (I had no time), ich musste gehen (I had to go) are all far more natural spoken than their Perfekt equivalents (ich bin müde gewesen, ich habe keine Zeit gehabt, ich habe gehen müssen), which exist grammatically but sound noticeably heavier in conversation. If you learn only one Präteritum set fluently for speaking, make it this one — it covers a disproportionate share of what actually gets said out loud.
Putting it together
A verb's full conjugation profile — Präsens, its er/sie/es form if it stem-changes, Präteritum, Partizip II, and its auxiliary — is really five separate facts that happen to share one infinitive. Weak, non-stem-changing verbs let you derive four of the five from the rules above; strong and stem-changing verbs need each fact checked and learned individually, which is exactly why the highest-frequency verbs (heavily strong, heavily irregular) reward direct memorization more than rule-application.
How WunderDict helps
When you look a word up in WunderDict and it's a verb, the conjugation comes back filled in — Präsens forms, Präteritum, Partizip II, and the auxiliary — rather than something you reconstruct from the rules above every time you need it. Save it to a list and the full profile travels with the word.
Looking a verb up in WunderDict fills in its conjugation grid, its Partizip II and the auxiliary it takes, so the principal parts are there when you save it to a list. It's part of the same free-account practice suite as the rest of WunderDict's quizzes — guest mode covers search and list-building, but scored practice needs an account. The 100 most common German verbs is a good place to start, since those are the verbs you'll actually need this system for most often. See the other guides for more.