He was elected as the Prime Minister of Japan.

His opinion is always rational.

I am surprised at the irrationality of this system.

This system is too irrational to understand.

This project requires a lot of work.

He believes that he is a psychic.

I learned how to calculate rational expressions in math class.

A kana ligature is one of the notation methods in Japanese.

He pointed out people's flaws, saying 'there are claws in the melon, but none in the claw.'

There are a lot of gac growing in my garden.