It is important to understand the importance of health.

Do you understand the necessity of this project?

It's difficult to understand his explanation.

Please fill out all the necessary information on the application form.

In order to understand the importance of the three Rs, it is necessary to learn the basics of reading, writing, and arithmetic.

He is good at arithmetic.

He does arithmetic every day.

It is important to learn the basic grammar of Japanese.

I like to study new languages.

It's difficult to understand his explanation.