The interjection 'Ah!' expresses his surprise.

He expresses numbers using numerals.

Yushi is my best friend.

That person is my friend.

He is very careful in his choice of diction.

He is very careful in choosing words and phrases.

A determiner plays a role in specifying a noun.

At his funeral, I read a eulogy for him.

There are several words used as 働詞 in this ancient document.

The word 'hatarakikotoba' is used in this old document.