German possessives ("my, your, his...") behave exactly like ein/kein - same endings, same der/die/das agreement. Once you know one, you know them all; only the stem changes.
| mein- | my |
| dein- | your (informal) |
| sein- | his/its |
| ihr- | her/their |
| unser- | our |
| euer- | your (informal plural) |
| Ihr- | your (formal) |
| Gender | Nominative | Accusative |
|---|---|---|
| masculine | mein | meinen |
| feminine | meine | meine |
| neuter | mein | mein |
| plural | meine | meine |
Das ist sein Auto. (his car, neuter)
Das ist ihre Tasche. (her bag, feminine)
Wie heißt euer Lehrer? (what's your [pl.] teacher called - masculine)
To avoid three vowels in a row, euer becomes eure (not "euere") when an ending is added: eure Wohnung, not "euere Wohnung."
Cross-checked against the Goethe-Institut A1 practice materials.