He is serious about wanting to learn Japanese.

He once participated in a war as an infantryman.

He did something foolish.

He did a foolish action.

He carved his name into the tree.

His actions revealed his criminal intent.

Pleurogrammus azonus is a type of fish that lives in cold waters.

We went to a hot spring for comfort over the weekend.

He went to a seaside town to recuperate after a long illness.

He suddenly had a paroxysmal attack.