My mother didn't have a computer when she was a child.
correct
We go to London last month.
We went to London last month.
I saved the photos on a memory key.
I saved the photos on a memory stick.
I gave my mother flowers.
correct
We didn't play computer games when we were two years old.
correct
My grandmother didn't wear jeans when she was a girl.
correct
They didn't had televisions 200 years ago.
They didn't have televisions 200 years ago.
She writed a letter to her friend.
She wrote a letter to her friend.
We was very happy yesterday.
We were very happy yesterday. / I was very happy yesterday.
I eat a pizza yesterday.
I ate a pizza yesterday.
I didn't played football when I was young.
I didn't play football when I was young.
He bought new headphones.
correct