The word ‘teacher’ is classified as a common noun.
Common nouns refer to general items, people, or concepts, as opposed to specific ones. In this case, ‘teacher’ describes a profession or role that can apply to many individuals rather than denoting a specific person. For example, when we say ‘the teacher is in the classroom,’ we are referring to any teacher, not a particular one. On the other hand, a proper noun would be a specific name, like ‘Mr. Smith’ or ‘Ms. Johnson,’ which identifies a particular individual. Therefore, ‘teacher’ is a general term and is a common noun.