Possessive Determiners (mein, dein, sein, ihr...)

German possessives — mein (my), dein (your), sein (his/its), ihr (her/their), unser (our), euer (your-plural), Ihr (your-formal) — look simple until you realize they ask you to track two things at once. The stem you pick depends on the owner; the ending you add depends on the thing owned. English never makes you do this — my, your, his stay frozen no matter what follows. This page teaches you to run both agreements at the same time, which is the single skill that makes German possessives click.

Two layers of agreement

Take the English sentence "his book." The word his tells you the owner is male, and that's the end of it — his book, his table, his children, all identical. German splits the job in two:

1. The stem announces the owner. sein- = a masculine or neuter owner (he / it); ihr- = a feminine owner (she) or a plural owner (they).
2. The ending agrees with the possessed noun's gender, case, and number — exactly as the article ein would.

So "his book" is sein Buch, but "his bag" is seine Tasche, because Buch is neuter (bare ein-word) and Tasche is feminine (ending -e). The owner didn't change — he's still male — but the ending tracks the noun, not him.

The stems: choosing by owner

First, lock in which stem matches which owner. This is a closed list — memorize it once.

Two collisions to notice. First, ihr- does triple duty: "her," "their," and (capitalized) "your-formal." Context and capitalization sort them out. Second, euer- drops its middle -e- the moment you add an ending: euer Haus but eure Wohnung, euren Garten — see the dedicated page on euer and unser stem changes.

Same noun, same sentence — only the owner's gender changes the stem from sein to ihr. This is the split English collapses into the single contrast his / her.

The endings: agreeing with the thing owned

Possessives are ein-words: they take the exact endings of the indefinite article ein, including the three bare spots where ein has no ending at all (masculine nominative, neuter nominative, neuter accusative). Here is mein fully declined — every possessive follows this grid:

Watch how the ending tracks the possessed noun, holding the owner constant. With mein (the owner is always "I" here), the noun does all the work:

Vater is masculine nominative → bare mein; Mutter is feminine → meine; Kind is neuter nominative → bare mein; Eltern is plural → meine. Four different endings (or none), one unchanging owner.

The ending also moves with case, just like the article. Watch mein shift as the case changes:

In the first, Bruder is masculine accusative → meinen. In the second, the verb helfen takes the dative → meinem. The owner never changed; the case did.

Running both agreements at once

Now combine the two layers. To say "her brother" in the accusative ("I'm calling her brother"), you: (1) pick the stem for a female owner → ihr-; (2) add the masculine-accusative ending → -en. Result: ihren Bruder.

In seine Großmutter, the owner is male (sein-) but the possessed noun Großmutter is feminine accusative, so the ending is -e: seine. The two layers point in different directions, and that is exactly the point — the stem looks back at er, the ending looks forward at Großmutter.

Here ihr means "their" (plural owner), and the possessed Auto is neuter accusative → bare ihr. Meanwhile unsere shows a plural possessed noun (Nachbarn) in the nominative.

euer and the formal Ihr

Two practical notes before the mistakes. euer contracts when it takes an ending — the unstressed -e- in the middle disappears: euer Auto but eure Tür, euren Hund, eurem Lehrer. Saying eueren or euerem is a common slip even among learners who know the rule.

The formal possessive Ihr is always capitalized, which is how writing distinguishes it from lowercase ihr ("her / their"). In speech they sound identical; only context tells them apart.

Common Mistakes

This is the number-one error: English speakers reach for seine because the owner is one specific person, treating the ending like a marker of the owner. But the ending agrees with Buch (neuter nominative → bare sein). The owner is already handled by the stem.

The owner is female (ihr-, correct), but Buch is neuter accusative → bare ihr, not ihre. Again: stem from the owner, ending from the noun.

English speakers default to sein (the most-drilled form) regardless of owner. Maria is female, so the stem is ihr-; Schlüssel is masculine accusative, so the ending is -en → ihren.

Neuter nominative is a bare spot, so euer takes no ending at all here. And when it does take one, it contracts: eure, euren, eurem — never eueres or eueren.

Possessives are bare only in three spots; masculine accusative is not one of them. Before Bruder as a direct object, dein must become deinen.

Key Takeaways

• Possessives are ein-words: they take ein-endings, with three bare spots (masc. nom., neut. nom., neut. acc.).
• Stem = owner (mein, dein, sein, ihr, unser, euer, Ihr). Ending = the thing owned (its gender, case, number).
• sein- = male/neuter owner; ihr- = female owner, plural owner ("their"), and — capitalized — formal "your."
• euer drops its middle -e- before any ending (eure, euren); formal Ihr is always capitalized.
• Run the two agreements separately, in order — owner first, then the noun — and seine Tasche will stop looking like a contradiction.