Denken ("to think") is one of a small, important group of mixed verbs — verbs that combine a strong-verb stem change with weak-verb endings. In the present it looks completely regular (denke, denkst, denkt), but the moment you go into the past the vowel shifts from -e- to -a- and the stem-final -k- softens to -ch-: dachte, gedacht. The other thing that trips up English speakers is its government: in German you don't think about something, you think an (literally "on") something, and an here takes the accusative.
Principal parts
| Infinitive | Präteritum | Partizip II (auxiliary) |
|---|---|---|
| denken | dachte | gedacht (hat) |
Read this as denken – dachte – hat gedacht. The endings (-te, ge-…-t) are exactly those of a weak verb; the stem (denk- → dach-) is what changes, which is why we call it mixed. The Perfekt auxiliary is haben.
Präsens (present)
Fully regular — no vowel change, no buffer vowel needed, because the stem denk- ends in a consonant cluster that takes endings cleanly.
| Person | Form |
|---|---|
| ich | denke |
| du | denkst |
| er / sie / es | denkt |
| wir | denken |
| ihr | denkt |
| sie / Sie | denken |
Ich denke oft an meine Großeltern.
I often think of my grandparents. (denken an + accusative)
Was denkst du über den Vorschlag?
What do you think about the proposal? (denken über is allowed for 'have an opinion on')
Präteritum (simple past)
The mixed past stem is dachte-. Notice that the k has become ch — a remnant of an ancient sound change shared with English think → thought.
| Person | Form |
|---|---|
| ich | dachte |
| du | dachtest |
| er / sie / es | dachte |
| wir | dachten |
| ihr | dachtet |
| sie / Sie | dachten |
The Präteritum dachte is very common even in speech, especially in the fixed frame Ich dachte, … ("I thought …") introducing a mistaken assumption.
Ich dachte, du kommst erst morgen.
I thought you weren't coming until tomorrow. (informal, correcting a wrong assumption)
Niemand dachte damals an die Folgen.
At the time, nobody thought about the consequences.
Perfekt (present perfect)
Built with the present of haben + gedacht.
| Person | Form |
|---|---|
| ich | habe gedacht |
| du | hast gedacht |
| er / sie / es | hat gedacht |
| wir | haben gedacht |
| ihr | habt gedacht |
| sie / Sie | haben gedacht |
Daran habe ich gar nicht gedacht — danke für den Hinweis!
I didn't think of that at all — thanks for pointing it out! (informal; daran = da- compound replacing 'an + it')
Ich habe die ganze Zeit an dich gedacht.
I was thinking about you the whole time.
Plusquamperfekt (past perfect)
Past of haben (hatte) + gedacht.
| Person | Form |
|---|---|
| ich | hatte gedacht |
| du | hattest gedacht |
| er / sie / es | hatte gedacht |
| wir | hatten gedacht |
| ihr | hattet gedacht |
| sie / Sie | hatten gedacht |
Ich hatte nicht daran gedacht, einen Schirm mitzunehmen.
I hadn't thought to bring an umbrella.
Futur I and Futur II
Futur I uses werden + denken; Futur II uses werden + gedacht haben.
| Person | Futur I | Futur II |
|---|---|---|
| ich | werde denken | werde gedacht haben |
| du | wirst denken | wirst gedacht haben |
| er / sie / es | wird denken | wird gedacht haben |
| wir | werden denken | werden gedacht haben |
| ihr | werdet denken | werdet gedacht haben |
| sie / Sie | werden denken | werden gedacht haben |
Die Leute werden denken, wir hätten uns gestritten.
People will think we've had a fight. (informal speculation)
Imperativ (commands)
| Addressee | Form |
|---|---|
| du | denk(e) |
| ihr | denkt |
| Sie | denken Sie |
Denk daran, das Licht auszumachen!
Remember to turn off the light! (informal; denk daran = 'keep it in mind')
Konjunktiv II (would think)
The Konjunktiv II takes the past stem dachte and adds an umlaut: dächte. It is used for hypothetical thoughts and is the formal counterpart of würde denken.
| Person | Form |
|---|---|
| ich | dächte |
| du | dächtest |
| er / sie / es | dächte |
| wir | dächten |
| ihr | dächtet |
| sie / Sie | dächten |
In everyday speech, the synthetic dächte sounds slightly bookish; many speakers prefer würde denken. But dächte survives robustly in the set phrase Ich dächte, … (literary/formal, meaning "I should think / I rather think").
Ich dächte, das versteht sich von selbst.
I should think that goes without saying. (formal/literary)
Konjunktiv I (reported speech)
Used in formal indirect speech; the base is denke, with the diagnostic er-form denke (no -t).
| Person | Form |
|---|---|
| ich | denke |
| du | denkest |
| er / sie / es | denke |
| wir | denken |
| ihr | denket |
| sie / Sie | denken |
Der Sprecher betonte, die Regierung denke nicht an Steuererhöhungen.
The spokesperson stressed that the government was not thinking of tax increases. (formal/journalistic Konjunktiv I)
Usage and government
The single most important pattern is denken an + accusative = "to think of / about." Here English uses of/about but German fixes the preposition as an, and although an is a two-way preposition, with denken it always takes the accusative (you are mentally "directing your thoughts toward" something — a metaphorical motion).
Denkst du noch an mich?
Do you still think of me? (an + accusative mich)
A second pattern, denken über + accusative, means "to have an opinion about" and is interchangeable with halten von. And sich (Dat.) etwas denken (reflexive) means "to imagine / suspect something": Das habe ich mir gedacht — "I thought as much."
When something replaces the noun after an, German contracts it into a da-compound: an das → daran, an + question → woran. So "I thought of it" is Ich habe daran gedacht, never an es.
Das habe ich mir gleich gedacht.
I thought as much right away. (reflexive sich denken = 'suspect/imagine')
Common idioms and fixed expressions
| Expression | English |
|---|---|
| Ich dachte, … | I thought … (correcting an assumption) |
| Wer hätte das gedacht! | Who would have thought! |
| Das habe ich mir gedacht. | I thought as much. |
| denken an (+ Akk.) | to think of / remember to |
| laut denken | to think out loud |
Wer hätte das gedacht — sie haben tatsächlich gewonnen!
Who would have thought — they actually won! (informal exclamation)
Common Mistakes
❌ Ich denke über meine Familie jeden Tag.
Incorrect preposition — 'to think of' someone is denken an, not denken über.
✅ Ich denke jeden Tag an meine Familie.
I think of my family every day.
❌ Ich denke an meinem Bruder.
Incorrect case — denken an governs the accusative, not the dative: an meinen Bruder.
✅ Ich denke an meinen Bruder.
I'm thinking of my brother.
❌ Ich habe gedenkt.
Incorrect participle — the mixed verb forms gedacht (k → ch), not 'gedenkt'.
✅ Ich habe gedacht.
I thought / I have thought.
❌ Ich denke an es.
Incorrect — a non-person after an is folded into a da-compound: daran.
✅ Ich denke daran.
I'm thinking about it.
❌ Ich denkte, es regnet.
Incorrect — the past of denken is the mixed dachte, never the regular 'denkte'.
✅ Ich dachte, es regnet.
I thought it was raining.
Key Takeaways
- Principal parts: denken – dachte – hat gedacht (mixed: stem denk- → dach-, weak endings; Perfekt with haben).
- Present is regular: denke, denkst, denkt.
- Government: denken an + accusative = "think of"; with a thing, use the da-compound daran.
- dächte is the Konjunktiv II; in speech würde denken is common, but Ich dächte survives as a formal set phrase.
- Don't confuse the mistaken-assumption frame Ich dachte, … with the opinion Was denkst du über …?
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