I forgot to pay the bus fare.

The train fare is high, making my monthly expenses tough.

When I was in my teens, I used to play soccer every day.

I looked for a cheap hotel to save on the cost of accommodation for my trip.

I looked for a cheap hotel to save on accommodation costs.

Learning irregular verbs is difficult.

He understands the meaning of the proverb 'Teaching is half learning', which means that teaching leads to one's own learning.

This is a once-in-a-lifetime opportunity.

He is a professor of algebra.

Yoshitoshi is my best friend.