mine
The word 'mein' in German is a possessive pronoun, used to indicate ownership or possession. It is equivalent to the English word 'mine'. However, unlike English, German has different forms of the possessive pronoun depending on the gender, number, and case of the noun it is modifying. 'Mein' is used when the noun is masculine and singular in the nominative or accusative case.
This is my book
In this sentence, 'mein' is used to show possession over the book. It is equivalent to the English word 'my', and is used before the noun it modifies.
My car is blue
In this sentence, 'mein' is used to indicate that the speaker is referring to their own car. Similar to the English 'my', it shows that the noun it precedes is possessed by the speaker.