This is a regular verb. It follows the conjugation pattern of the verb vivir.
PresentPresente
Ahora comparto piso con dos amigas.
Now I share an apartment with two friends.
PreteritePretérito indefinido
Ayer compartimos una pizza enorme.
Yesterday we shared a huge pizza.
ImperativeImperativo afirmativo
Por favor, comparte tus apuntes con Marta.
Please share your notes with Marta.