This is the 20th most frequent French word.
ses
"Ses" means "his," "her," or "its" when referring to plural nouns.
The word 'ses' is a possessive adjective referring to 'her' and it signifies that the books belong to 'her' (third-person singular feminine subject).
Elle a pris ses livres pour la classe.
She took her books for the class.
The word 'ses' is a possessive adjective referring to 'his' and it signifies that the responsibilities belong to 'him' (third-person singular masculine subject).
Il a pensé à ses responsabilités professionnelles.
He thought about his professional responsibilities.
The word 'ses' is a possessive adjective referring to a singular noun (ideas) collectively belonging to the plural subject 'They' ('Ils').