The Adjective-Ending System Unified

If you have read the weak, strong, and mixed pages, you now hold three tables in your head — and three tables are exactly two too many to use under the pressure of live conversation. This page collapses them into a single idea and a single decision procedure. Once you see the principle underneath, you will stop memorizing tables and start deriving the right ending on the fly. This is, for most learners, the moment German adjective endings finally click.

The one principle

Here is the whole system in a sentence:

The grammatical case must be marked strongly exactly once in the noun phrase — no more, no less.

A German noun phrase is a small team: a determiner (article) and an adjective standing in front of a noun. The job of showing the case — that strong, informative ending like -er, -es, -em, -en, -er — has to be done once by the team. German is economical: it does not want the case marked twice, but it absolutely will not let it go unmarked.

So the question becomes simple: who on the team is marking the case?

• If the determiner is already marking it strongly, the adjective backs off and takes a neutral, low-information ending (-e or -en). That is the weak declension.
• If there is no determiner, the adjective is the only player left, so it must mark the case strongly itself. That is the strong declension.
• If there is a determiner but it fails to mark the case in a particular cell (the three endingless ein forms), the adjective steps in just for those cells and marks it strongly. That is the mixed declension.

Weak, strong, and mixed are not three separate systems. They are three answers to one question: is the case already marked, or do I have to mark it?

The three-step decision procedure

When you are about to put an ending on an attributive adjective, run these three steps:

1. What comes immediately before the adjective?
   • A der-word (der, dieser, jeder, welcher, alle …) → go to step 2a.
   • An ein-word (ein, kein, mein, dein …) → go to step 2b.
   • Nothing → go to step 3.

2a. (der-word) The case is already marked. Use the weak ending: -e in the five top-left cells (nominative singular all genders; accusative feminine and neuter), -en everywhere else.

2b. (ein-word) Is this one of the three endingless gaps — nominative masculine, nominative neuter, or accusative neuter?

• Yes → the ein-word marks nothing here, so you supply the strong ending (-er for nom. masc., -es for nom./acc. neut.).
• No → the ein-word is inflecting and marking the case, so use the weak ending (-en, or -e in nom./acc. feminine).

3. (no article) You are the only marker. Use the strong ending, which mirrors the definite article (der → -er, das → -es, dem → -em), with the single exception that genitive masculine/neuter is -en (the noun's own -(e)s does that job).

Three steps, and every cell of all three tables is accounted for.

All three side by side

Seeing the patterns in one frame makes the relationship obvious. Here is gut across all four cases in the masculine singular, under each of the three conditions:

Now read across the nominative row. The weak column has -e because der already shouts "nominative masculine." The strong column has -er because nothing else is there to shout it. And the mixed column has -er too — because ein is one of the silent forms here, so the adjective behaves exactly as it does in the strong column. The first row is precisely where mixed copies strong.

Now read across the accusative, dative, and genitive rows. The weak and mixed columns are identical — both -en — because in those rows the der-word and the ein-word are both inflecting and both marking the case. Mixed only ever diverges from weak in that one nominative cell (for masculine). The strong column, meanwhile, keeps marking the case itself: -en, -em, -en.

This is the entire system, visible in one square. Mixed is weak that borrows from strong in the gaps; strong is the fallback when nobody else will mark the case.

Worked examples

Run the procedure on real phrases and watch it generate the ending.

Starken sits after einen (an ein-word). Is accusative masculine a gap? No — ein inflects to einen here, marking the case. So: weak -en. Correct.

Frische has no article in front (Brötchen is a bare plural). So the adjective is the only marker → strong. Nominative plural strong is -e: frische. Correct.

Älteren follows meines (an ein-word), genitive masculine. Is genitive masculine a gap? No — ein inflects to eines/meines here. So: weak -en: älteren. Correct. (Note also the lowercase ä with the umlaut — älter is the comparative of alt.)

Two adjectives, two different answers. Gemütliches follows ein in the accusative neuter — that is a gap, so strong -es. Gutem follows mit with no article (mit takes dative; Kuchen has no article) — so the adjective is the sole marker → strong dative masculine -em. Both strong, for two different reasons.

Alten follows diesem (a der-word) in the dative. Case already marked → weak. The whole dative is -en in the weak declension: alten. Correct.

Why this principle is worth trusting

It is tempting to dismiss "mark the case once" as a tidy after-the-fact story. It is not. It is genuinely predictive — it tells you the right ending in phrases you have never seen, and it explains every apparent oddity:

• Why is strong genitive masculine -en and not -es? Because the noun's own -(e)s (Weines) already marks the case; marking it again would be redundant.
• Why is the mixed plural always weak? Because there is no bare ein in the plural — the plural ein-word always inflects and always marks the case, leaving no gap.
• Why does masculine cause the most trouble? Because masculine is the only gender whose der-word and ein-word change between nominative and accusative (der/den, ein/einen), so it is the only gender where the adjective ending shifts mid-paradigm.

Every one of these is a consequence of the same rule. There is no separate fact to learn.

English contrast

English carries case on pronouns only (he/him, she/her) and never on adjectives, so the entire enterprise of "marking case in the noun phrase" has no English parallel. The nearest intuition is redundancy avoidance, which English does practice elsewhere: we say "he runs" but "they run," dropping the -s once the plural subject makes the number clear. German extends that economy to case inside the noun phrase. If you can accept "the case has to show up once, and the words negotiate who shows it," you have understood German adjective endings more deeply than most of the tables ever convey.

Common Mistakes

The most damaging habit is mental: learners memorize three separate grids and then stall mid-sentence trying to retrieve the right one. Replace the three grids with the single question above and the hesitation disappears.

The principle pinpoints why: ein (nom. masc.) marks nothing, so the adjective must, with strong -er. Defaulting to weak -en leaves the case unmarked.

Here the learner correctly senses "dative needs -em" but applies it on top of dem, which has already marked the dative. The case is marked once — by dem — so the adjective weakens to -en. Double-marking is just as wrong as no marking.

No article means the adjective is the sole marker, so it must carry the dative strong ending -em, not the nominative -er. The principle forces you to ask not just "is the case marked?" but, when the answer is "I must mark it," which case — and to supply the right strong ending for it.

Key Takeaways

• One principle governs everything: the case is marked strongly exactly once in the noun phrase.
• Run three steps: (1) what precedes the adjective? (2) is the case already marked there? (3) if not, the adjective marks it strongly.
• der-word → weak; no article → strong; ein-word → weak, except strong in the three endingless gaps (nom. masc., nom./acc. neut.).
• Mixed is just weak that borrows the strong ending wherever ein is silent; it diverges from weak in only one cell (nominative masculine).
• Every "exception" (strong genitive -en, the always-weak plural, the troublesome masculine) follows from the single rule — none of them is a separate fact to memorize.