Ubah ke passive voice I didn't give a present to my sister My uncle buys a tshirt and trouser Jones wrote a letter to his mother Does he help his mother?

a present wasn't given to my sister (by me).
a t-shirt and trousers aren't bought by my uncle.
a letter was written by jones to his mother.
is his mother helped (by him)?

my sister was not given a present by me.
a tshirt and trouser is bought by my uncle.
a letter was written by Jones to his mother
is his mother helped by him?