Atsumu forgot to turn off the light.

My vocabulary is increasing every day.

He said, 'It's difficult to make a life,' explaining the phrase 'When a man steps over the threshold, he has seven enemies.'

Atsumu is immersed in compiling a dictionary.

Asymmetric Digital Subscriber Line provides high-speed internet connection.

It's difficult to handle this machine.

He continued to explain earnestly.

Atsushi is my classmate in junior high school.