We booked a double room.

Doublet is an important concept in linguistics.

I overslept today, so I was late.

He accepted the proposal without dispute.

He holds dual citizenship in America and Japan.

I will turn twenty years old next year.

I accidentally dropped the eye drops from the second floor.

He chose to serve a second master by working hard.

I learned the meaning of 'ichi ni ten' in the classical Japanese class.

His actions always have a duality.