Question

Are high school classes like freshman, sophomore, junior, senior proper nouns?

Answer 1

No, they are not proper nouns.

Explanation:

The classes of freshman, sophomore, junior, and senior are common nouns, not proper nouns.

• Common nouns name general things, and do not require capitalization.
  `rarr` waterfall, man, month, restaurant
• Proper nouns name specific things, and require capitalization.
  `rarr` Niagara Falls, Walt Disney, March, Bob Evans

Since freshman, sophomore, junior, and senior are not capitalized, they are common nouns.

Here is a video on common vs. proper nouns that is helpful to watch.