Selena bought a cat for her little sister
The word "I" is used for the subject of a sentence: I went to the store. You and I bought the book. The word "Me" is used for the object of a sentence, phrase, etc. He bought it for me.
We bought coffee as well as tea.
I bought a brand of bread.
He bought a colouring book for his daughter.
Jack bought a quart of milk.
She bought beautiful silk damask curtains.
I bought an apple and an elephant at the African store in Africa.
My dad bought me an amulet for my birthday
he bought the estate and all its appurtenances
The cheap knife I bought broke and was a gimcrack.
My mum bought me a assorted pack of biscuits.
he knew the stock was a speculation when he bought it