This is the 9471st most frequent Russian word.
уильяма
"Уильяма" is the genitive or accusative case of "Уильям," the Russian form of the name "William."
In this sentence, 'у Уильяма' uses the genitive case to indicate possession or association with William's location.
Я прочитал книгу у Уильяма.
I read a book at William's place.
In this sentence, 'Уильяма' is the accusative case, indicating William is the object of the action.
Уильяма позвали на вечеринку.
William was invited to the party.
In this sentence, 'для Уильяма' indicates the recipient of the gift, using the genitive case.