mi embarque - my shipment

nuestro arreglo - our arrangement

su sinceridad - his, her, or their sincerity

tu beneficio - your benefit

sus fondos - his funds (money)

Nuestro libro es interesante. - Our book is interesting.

Nuestros libros son interesantes. - Our books are interesting.

Nuestra madre vive en Madrid. - Our mother lives in Madrid.

Nuestras madres viven en Madrid. - Our mothers live in Madrid.

Vuestro perro está allí. - Your dog is there.

Vuestros perros están allí. - Your dogs are there.

Vuestra silla está allí. - Your chair is there.

Vuestras sillas están allí. - Your chairs are there.

Some sentences can have several different meanings. The context of the sentence will determine the proper meaning.

Su papá está aquí.
His father is here.
Her father is here.
Your (formal) father is here.

Sus papás están aquí.
His parents are here.
Her parents are here.
Your (formal) parents are here.

Su padre necesita ayuda.
Your (formal) father needs help.
Their (formal) father needs help.

Sus padres necesitan ayuda.
Your parents need help.
Their parents need help.