He did his best to protect his younger brother.

This verb is a godan conjugation.

He sent a message using Morse code.

He is writing a paper on coding theory.

He became a wealthy person by succeeding in business.

What does this sign mean?

A dependent, or affix, is a grammatical element that depends on the main word.

Using this acute accent changes the pronunciation.

I am surprised at the irrationality of this system.

This system is too irrational to understand.