I was in Japan last week.
I wasn't in Japan last week.
I was in China last week.
I wasn't in China last week,
He was 12 years old last year.
He wasn't 12 years old last year.
He was in the baseball club last year.
He wasn't in the baseball club last year.
I was happy yesterday.
I wasn't happy yesterday.
Ken was cool last year.
Ken wasn't cool last year.
She was a teacher 20 years ago.
She wasn't a teacher 20 years ago.
She was busy last night.
She wasn't busy last night.
It was snowy last week.
It wasn't snowy last week.
You were free yesterday.
You weren't free yesterday.
We were friends 10 years ago.
We weren't friends 10 years ago.
Ken and Taro were at school last night.
Ken and Taro weren't at school last night.
They were in Korea last month.
They weren't in Korea last month.
We were singers 30 years ago.
We weren't singers 30 years ago.
They were nice friends 20 years ago.
They weren't nice friends 20 years ago.
It was windy last night.
It wasn't windy last night.
You were sleepy yesterday.
You weren't sleepy yesterday.
It was sunny this morning.
It wasn't sunny this morning.