This is the 1377th most frequent Turkish word.
topu
"Topu" in Turkish means "the ball" or "its/his/her ball," depending on the context.
The word 'topunu' is the form of 'top' (ball) with a third person possessive suffix (-u) and the accusative case (-nu), indicating it belongs to someone (Ahmet) and is the direct object of the sentence.
Ahmet topunu bahçede oynuyor.
Ahmet is playing with his ball in the garden.
The word 'topu' here is the accusative form of 'top' (ball), indicating it is the direct object of the verb 'tercih etti' (preferred).
Kum torbasına vurmak yerine topu tercih etti.
Instead of hitting the sandbag, he preferred the ball.
In this sentence, 'topu' is again in the accusative case, showing it as the direct object of the verb 'attım' (threw).