That reminds me of a very interesting grammar point we should talk about...
*sigh* It was too good to be true...
Voilà ton café et voici mon café.
This is your coffee and here's my coffee.
Voilà ton café et voici le mien.
This your coffee and here's mine.
To avoid repeating the same noun twice in one sentence, you should think of ways to replace one of them.
And when you express possession with a noun (for instance: my coffee, your coffee, his/her coffee...), it can be replaced by what is called a possessive pronoun.
The possessive pronoun replaces possessive adjective and a noun!
Mon café =Le mien
Voici mon café.
→
Voici le mien.
Voici mes sacs.
→
Voici les miens.
Voici ma voiture.
→
Voici la mienne.
Voici mes chaussettes.
→
Voici les miennes.
What about yours and his/hers?
No worries, they follow the same rule as mine: le tien (yours) and le sien (his/hers).
La chaise bleue est la mienne, la rouge est la tienne.
The blue chair is mine, the red one is yours.
Tes stylos sont dans ta chambre, les miens sont sur la table.
Your pens are in your room, mine are on the table.
Mon chien est rapide, le sien est lent.
My dog is fast, his/hers is slow.
J'ai déjà mangé mes olives, je peux manger les tiennes?
I already ate my olives, can I eat yours?
You need to talk about the same thing/animal or person to use the possessive pronouns!
Mon chat est malade, le sien aussi.
My cat is sick, his/hers too. (both cats are sick)
Mon chat est malade, son chien aussi.
My cat is sick, his dog too. (a cat and a dog are sick)