At that time, I was still a student.

His success had a cause-and-effect relationship with his efforts.

By learning the imperfective form, you can understand Japanese grammar more deeply.

Using exalted language in Japanese is an important way to show respect to the other person.

He is a person who never forgets to respect others.

The radius of this circle is 5 centimeters.

We have maintained a good relationship for a long time.

Linear algebra is a branch of mathematics that studies the theory of vector spaces and linear transformations.

He has a deep interest in metaphysics.

He drew a pentagon on the blackboard.