Das ist mein Hund.
English: That is my dog.
Possessivpronomen in German are words like 'mein', 'dein', 'sein', etc., that show who owns or has something. They are used to say 'my', 'your', 'his', etc. in German.
Use German possessive pronouns to show that something belongs to someone. They are used before nouns to say whose thing it is, for example, 'my book' or 'your friend'.
Das ist mein Hund.
English: That is my dog.
Wo ist dein Schlüssel?
English: Where is your key?
Sein Auto ist blau.
English: His car is blue.
Unsere Lehrerin ist nett.
English: Our teacher is nice.
Ist das euer Haus?
English: Is that your (plural) house?