the word underground is a common noun but if used like Underground Railroad then it is proper
No, the compound noun 'underground river' is a common noun, a word for any underground river anywhere. A proper noun is the name of a person, a place, a thing, or a title. The River Fleet is an underground river that runs under London, UK. The River Fleet is a proper noun.
As a name of a road , Park Avenue', it is a proper noun, and both words star with a capital letter. However, when used separately, as 'the park, or 'the avenue', they are common nouns and so not need a capital letter.
Yes, "well" is a common noun when referring to a source of water found underground. It becomes a proper noun when used to refer to a specific location or landmark.
It is a proper noun, because it is the name of a specific thing.
Proper noun
proper
it's a common noun. a proper noun would be Spider-Man.
Pencil proper or common noun
The noun cassette is a common noun.
a common noun?
Camel is a common noun.
The answer is proper noun. Examples of common noun and proper noun are: Proper noun: Mary Collins Common noun: monkey