"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Yes, the word 'Irish' is a proper noun as a word for the people of Ireland as a group; as a word for the language of Ireland.The word 'Irish' is the proper adjective form of the proper noun Ireland. The adjective Irish describes someone or something of or from Ireland.
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
Pencil proper or common noun
it's a common noun. a proper noun would be Spider-Man.
Proper noun or common noun
Ireland is a proper noun.
The noun cassette is a common noun.
a common noun?
Camel is a common noun.