They thought the lesson was easy. (the homework)
They didn't think the lesson was easy, they thought the homework was easy.
Make the negative - thought
didn't think
He lost his mobile phone yesterday morning. (wallet)
He didn't lose his mobile phone yesterday morning, he lost his wallet yesterday morning.
Make the negative - waited
didn't wait
She did yoga last Friday. (judo)
She didn't do yoga last Friday, she did judo.
I took the bus to work last week. (the train)
I didn't take the bus to work last week, I took the train.
Make the negative - looked
didn't look
Make the negative - paid
didn't pay
Make the negative - put
didn't put
Make the negative - brought
didn't bring
Make the negative - sat
didn't sit
Make the negative - made
didn't make
She lent him a book yesterday. (a pen)
She didn't lend him a book yesterday, she lent him a pen.
We slept at our aunt's house last night. (niece's house)
We didn't sleep at our aunt's house last night, we slept at our niece's house.
I borrowed some money from him last week. (last month)
I didn't borrow some money from him last week, I borrowed some money last month.
Make the negative - said
didn't say
My mother made a cake for my birthday last year. (two years ago)
My mother didn't make a cake for my birthday last year, she made a cake 2 years ago.
I went shopping two days ago. (swimming)
I didn't go shopping two days ago, I went swimming.