Adjective Ending Errors

English adjectives never change shape: a good man, the good men, with the good man — good is good every time. That single fact produces both of the classic German adjective errors, and they pull in opposite directions. Beginners under-inflect, leaving attributive adjectives bare (der gut Mann), because English never adds an ending. Slightly more advanced learners over-correct and over-inflect, slapping an ending onto a predicate adjective (Der Mann ist guter), because they have learned "German adjectives take endings" too zealously. The cure for both is one rule: inflect an adjective only when it sits directly in front of a noun; never after sein, werden, or bleiben.

Error 1: Leaving attributive adjectives bare

When an adjective stands directly before the noun it describes, it must carry an ending. The ending encodes gender, case, and number, so dropping it is not a small slip — it leaves the phrase grammatically incomplete to a German ear.

Error 2: Inflecting predicate adjectives

The mirror-image mistake. After the linking verbs sein (to be), werden (to become), and bleiben (to stay/remain), the adjective is a predicate adjective and stays completely bare — no ending, ever. Learners who have internalized "German adjectives inflect" wrongly extend that to predicates, producing Der Mann ist guter.

Error 3: The wrong ending after ein-words

Once you accept that attributive adjectives need endings, the next trap is which ending. The shape depends on whether the adjective follows a der-word (definite article, dieser, jener) or an ein-word (ein, kein, and the possessives mein, dein, etc.). The critical insight is the "gap" rule: when an ein-word has no ending of its own to show gender/case, the adjective must step in and carry the strong ending instead. This happens in exactly three spots — masculine nominative, and neuter nominative and accusative.

Compare with the neuter, where the gap-filler genuinely is -es:

Contrast all of these with the der-word version, where the article already shows the case, so the adjective relaxes into the weak ending -e:

Error 4: Case mismatch on the adjective

The adjective ending also reflects case, so an adjective that is correct in the nominative is wrong in the accusative or dative. English speakers who have nailed the nominative often forget to shift the ending when the noun phrase changes role.

Error 5: Stacked adjectives must agree with each other

When two or more adjectives modify the same noun, they all take the same ending — learners often inflect the first and forget the second, or mix endings.

The minimal ending tables

You do not need to memorize all 48 cells before you can speak — most early errors are the under/over-inflection ones above. But here are the patterns the examples draw on. After a der-word the endings are weak (mostly -e and -en):

After an ein-word the endings are mixed — identical to the weak ones except in the three gap cells, where the strong ending appears:

The bold cells in the mixed table (-er, -es, -es) are exactly the spots where ein shows no marking and the adjective takes over. That is the whole "gap" logic.

Why German works this way

German nouns need their gender and case marked somewhere in the noun phrase. Usually the article does the job (dem already screams "dative"), so the adjective can take a featureless weak ending. But when the article is missing or, like ein, fails to mark gender (it is bare in the masculine and neuter nominative), the burden shifts to the adjective, which then carries the strong, fully-marking ending. The system is economical: exactly one element marks the case, and the adjective fills in only when nothing else has. Predicate adjectives, by contrast, describe the subject through a linking verb rather than sitting inside a noun phrase — there is no case for them to mark, so they stay bare. Seeing inflection as case-marking that travels to whichever slot needs it explains both why attributives must inflect and why predicates must not.

Common Mistakes

Key Takeaways

• Inflect before a noun; stay bare after sein, werden, bleiben. This one rule fixes both the under-inflection and over-inflection errors.
• After der-words, endings are weak (-e / -en); after ein-words they are mixed — weak everywhere except the three gap cells (masc. nom. -er, neut. nom./acc. -es), where the adjective takes the strong ending.
• The ending also marks case, so it changes when the noun phrase shifts from nominative to accusative or dative (ein guter Mann → einen guten Mann).
• Stacked adjectives all take the same ending (der gute alte Mann).
• Think of the ending as case-marking that travels to whichever element needs to carry it; predicates have no case to mark, so they take nothing.