This project is focused on a single goal.

He doesn't waste even a single grain of rice.

He knows nothing about that one case.

One part is important.

He read the Thousand and One Nights and was drawn to the charm of the Orient.

He said, 'Each person has one life, like a pike or a shrimp,' and decided to live his life with care.

Thinking sensibly, that plan will not succeed.

This is a preliminary plan.

He is interested in diachronic linguistics studies.

He is interested in synchronic linguistics.