When learning Japanese grammar, it is important to understand verbs of the upper monograde conjugation.

He acted according to my instructions one by one.

The first day of the month is the beginning of a new month.

I have been to France once.

His first choice of school is the University of Tokyo.

I went to see a movie by myself.

He has a competitive spirit that does not allow even one defeat.

He finished all his work all at once.

Watching a movie alone is enjoyable.

I ate one apple.