教室

In a sentence

• 教室の中には生徒がたくさんいます。

  There are many students inside the classroom.

  Here, '教室' refers to the physical classroom space.

• 私は日曜日にピアノ教室に通っています。

  I attend piano classes on Sundays.

  In this sentence, '教室' represents a specific type of class or lesson.

• 教室の飾り付けがとてもきれいですね。

  The decorations in the classroom are very beautiful.

  Here, '教室' is used to describe the physical classroom environment.