Noun Declension Review Across All Cases
German nouns change their form — and the article in front of them — depending on which of the four cases they appear in. By B1, you have seen Nominative, Accusative, Dative, and Genitive many times; this lesson ties them together and highlights exactly where learners most often slip up.
The trickiest area is a small but very common group called weak masculine nouns (n-Deklination). Unlike regular nouns, these add -en or -n in every case except the Nominative singular. Mastering this pattern will make your German noticeably more accurate and natural.
The Four Cases: A Quick Refresher
Every German noun and its article change according to the noun's grammatical role in the sentence. There are four cases:
| Case | Role | Key question | Example |
|---|---|---|---|
| Nominative | subject | Wer/Was? | Der Mann schläft. |
| Accusative | direct object | Wen/Was? | Ich sehe den Mann. |
| Dative | indirect object | Wem? | Sie hilft dem Mann. |
| Genitive | possession | Wessen? | Das Auto des Mannes. |
For regular masculine nouns, the noun itself only changes in the Genitive singular, where it gains -s or -es (e.g., des Mannes, des Tisches). The articles — der / den / dem / des — carry most of the case information.
Weak Masculine Nouns (n-Deklination)
A specific set of masculine nouns follows the weak declension pattern. They add -en (or just -n when the noun already ends in -e) in the Accusative, Dative, and Genitive singular, and in all plural forms.
Declension of der Student (ends in consonant) and der Kollege (ends in -e):
| Case | der Student | der Kollege |
|---|---|---|
| Nominative sg. | der Student | der Kollege |
| Accusative sg. | den Studenten | den Kollegen |
| Dative sg. | dem Studenten | dem Kollegen |
| Genitive sg. | des Studenten | des Kollegen |
| Nominative/Accusative pl. | die Studenten | die Kollegen |
| Dative pl. | den Studenten | den Kollegen |
| Genitive pl. | der Studenten | der Kollegen |
Quick rule: If the noun appears anywhere other than the subject position AND it is a weak masculine, add -en (or -n).
Common Weak Masculine Nouns
These are the most frequently encountered weak masculine nouns at B1 level:
| Nominative | Meaning | Acc./Dat./Gen. sg. |
|---|---|---|
| der Student | student | den/dem/des Studenten |
| der Kollege | colleague | den/dem/des Kollegen |
| der Herr | Mr. / gentleman | den/dem/des Herrn |
| der Mensch | person / human | den/dem/des Menschen |
| der Polizist | police officer | den/dem/des Polizisten |
| der Patient | patient | den/dem/des Patienten |
| der Präsident | president | den/dem/des Präsidenten |
| der Zeuge | witness | den/dem/des Zeugen |
| der Journalist | journalist | den/dem/des Journalisten |
| der Nachbar | neighbour | den/dem/des Nachbarn |
Special note on Herr: It adds only -n in the singular (den Herrn) but -en in the plural (die Herren). Nouns ending in -e (Kollege, Zeuge) almost always belong to this group.
Choosing the Right Case: A Checklist
Use these four questions whenever you write a masculine noun:
- Is it the subject? → Nominative — no ending change (Der Student kommt).
- Is it a direct object? → Accusative — regular nouns unchanged; weak nouns add -en/-n (Ich sehe den Studenten).
- Is it an indirect object or follows a dative preposition (mit, bei, nach, aus, von, seit, zu, gegenüber)?→ Dative — regular nouns unchanged; weak nouns add -en/-n (Er hilft dem Studenten).
- Does it show possession? → Genitive — regular nouns add -s/-es; weak nouns add -en/-n instead (das Buch des Studenten).
| Regular noun (der Mann) | Weak noun (der Student) | |
|---|---|---|
| Nom | der Mann | der Student |
| Acc | den Mann | den Studenten |
| Dat | dem Mann | dem Studenten |
| Gen | des Mannes | des Studenten |
📖 Examples
Der Student lernt jeden Abend Deutsch.
The student studies German every evening. (Nominative — subject)
Ich sehe den Studenten in der Bibliothek.
I see the student in the library. (Accusative — direct object)
Der Professor erklärt dem Studenten die Grammatik.
The professor explains the grammar to the student. (Dative — indirect object)
Das Buch des Studenten liegt auf dem Schreibtisch.
The student's book is lying on the desk. (Genitive — possession)
Sie spricht mit dem Kollegen über das neue Projekt.
She is talking with the colleague about the new project. (Dative — after preposition *mit*)
Der Zeuge hat alles genau beobachtet.
The witness observed everything closely. (Nominative — subject)
Die Ärztin behandelt den Patienten sehr sorgfältig.
The doctor treats the patient very carefully. (Accusative — direct object)
Das Auto des Nachbarn steht vor unserem Haus.
The neighbour's car is parked in front of our house. (Genitive — possession)
⚠️ Common Mistakes
Ich kenne den Student gut.Ich kenne den Studenten gut.
'Student' is a weak masculine noun. In the Accusative (direct object), it must add -en: 'den Studenten'. English speakers often treat it like a regular noun and leave it unchanged.
Er spricht mit dem Herr.Er spricht mit dem Herrn.
'Herr' follows the weak declension. After a dative preposition like 'mit', the dative singular form is 'dem Herrn', not 'dem Herr'. The -n ending is mandatory.
Das ist das Büro des Präsidentes.Das ist das Büro des Präsidenten.
Weak masculine nouns take -en in the Genitive, not the regular -es ending. 'Präsident' is weak, so the Genitive is 'des Präsidenten'. Using -es is the regular pattern and does not apply here.
Das Auto des Nachbars ist neu.Das Auto des Nachbarn ist neu.
'Nachbar' belongs to the weak declension group. Its Genitive adds -n: 'des Nachbarn'. Applying the regular masculine Genitive ending -s ('des Nachbars') is a typical but incorrect transfer from regular nouns.
✏️ Exercises
Test your understanding. Click an option or type your answer, then check.
Choose the correct form: 'Ich sehe ___ (der Student) in der Mensa.'
Which form is correct? 'Das Büro ___ (der Präsident) ist im dritten Stock.'
Which of the following is a weak masculine noun?
Choose the correct form: 'Die Krankenschwester bringt ___ (der Patient) sein Frühstück.'
Which sentence uses 'Herr' correctly?
Which Genitive form is correct for the regular masculine noun 'der Mann'? 'Das Fahrrad ___ ist rot.'
Ich treffe ___ (der Kollege) morgen um neun Uhr.
Der Richter befragt ___ (der Zeuge) sehr genau.
Der Name ___ (der Journalist) steht in der Zeitung.
___ (der Mensch) braucht ausreichend Schlaf, um gesund zu bleiben.