This is the 124th most frequent Croatian word.
njegova
"Njegova" means "his" in English.
The word 'njegova' stands for 'his', showcasing possession of an abstract noun 'odgovornost' (responsibility), which is feminine.
Njegova odgovornost je ogromna.
His responsibility is enormous.
The word 'njegova' denotes possession and agrees with the gender (feminine) of the noun 'knjiga' (book).
Njegova knjiga je na stolu.
His book is on the table.
The word 'njegovu' is the accusative form of 'njegova', used here to indicate the direct object, and it agrees with the gender (feminine) of the noun 'sestru' (sister).