Determiners: der-words and ein-words

A determiner is the little word that opens a noun phrase: the, a, this, every, my, no. In German these words are not decorative — they carry case, and they decide what ending any following adjective will take. The whole sprawling system of German adjective endings collapses into something manageable once you sort determiners into just two families: der-words and ein-words. Knowing which family a determiner belongs to tells you, almost instantly, how the adjective after it behaves. This page is the master key to that system.

Two families, two patterns

Every determiner in German declines like one of two model words:

• der-words decline like the definite article der / die / das. This family includes dieser (this), jeder (each/every), jener (that), welcher (which), mancher (many a/some), solcher (such), and alle (all). Because these words already show the case clearly on their own ending, the adjective after them can afford to be "lazy" — it takes the weak endings (mostly -e and -en).

• ein-words decline like the indefinite article ein. This family includes ein (a), kein (no/not a), and all the possessives: mein (my), dein (your), sein (his/its), ihr (her/their), unser (our), euer (your-plural), Ihr (your-formal). In three spots, the ein-word itself has no ending at all, so the adjective has to step up and show the case — that's the mixed pattern.

The der-word pattern: dieser

A der-word takes exactly the endings of the definite article. Here is dieser ("this"), the model der-word, in all four cases:

Compare that, cell for cell, with der / die / das: the endings are identical (-er, -e, -es, -en, -em, -er). That's why jeder, welcher, mancher and the rest are called der-words — swap the stem, keep the endings.

In dieser gute Mann, the der-word dieser already shows nominative masculine clearly, so the adjective gut relaxes into the weak ending -e: gute. And in jedem Nachbarn, jeder takes the dative -em just like dem.

The ein-word pattern: mein

An ein-word takes the endings of the indefinite article ein — and the catch is that ein has no ending in three key spots: masculine nominative, neuter nominative, and neuter accusative. Here is mein ("my"), the model possessive, fully declined:

Look at the three bare cells: mein (masc. nom.), mein (neut. nom.), mein (neut. acc.). In those exact spots the determiner can't tell you the gender or case, so the adjective has to — it takes the strong ending there (-er for masculine, -es for neuter). Everywhere else, the ein-word shows the case and the adjective relaxes to -en (or -e). That mix of strong-in-three-spots, weak-elsewhere is precisely the mixed declension.

Here mein is bare (masc. nom.), so gut must carry the strong masculine ending -er: guter. Contrast that directly with the der-word version: dieser gute Freund — there dieser already shows the -er, so the adjective is the weak gute.

Kein is an ein-word; before neuter Brot it is bare (kein), so frisch takes strong -es: frisches.

Seeing the families side by side

The clearest way to feel the difference is to put the same adjective and noun behind a der-word and an ein-word:

The only rows where the two families genuinely diverge are the bare-determiner spots (masc. nom., neut. nom., neut. acc.). Everywhere else the adjective ends in -en or -e either way. So the "two patterns" are really one pattern with three exceptions clustered in the ein-word family.

Common Mistakes

Because English this never changes, learners leave the German der-word bare. But dieser declines exactly like der; the masculine nominative form is dieser, never bare dies. (Bare dies exists only as a fixed neuter pronoun, as in Dies ist mein Haus.)

This is the classic ein-word slip. Since mein shows nothing here, the adjective must carry the strong masculine ending -er. Using -en (the der-word reflex) is wrong precisely because mein didn't do the job dieser would have.

The mirror error: applying the ein-word ending after a der-word. Since dieser already shows -er, the adjective relaxes to weak gute.

(Welch without an ending survives only in elevated exclamations like Welch ein Glück! — "What luck!" — which is literary.)

Even ein-words show case in most cells. Before masculine accusative Bruder, dein must become deinen.

Key Takeaways

• German determiners split into der-words (decline like der/die/das) and ein-words (decline like ein, with three bare spots).
• der-words trigger weak adjective endings; ein-words trigger mixed endings.
• The two patterns differ only in the three bare ein-word spots (masc. nom., neut. nom., neut. acc.), where the adjective takes the strong ending.
• Identifying the family is the fast track to choosing the right adjective ending — learn this distinction before drilling endings one by one.