Well, darling, "hen" is actually a gender-neutral pronoun used in place of "he" or "she." So, it's not about being common or proper, it's about being inclusive and respectful. So, go ahead and use "hen" if you want to keep up with the times and show some consideration for all gender identities.
proper
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.
common
It is a proper noun, because it is the name of a specific thing.
common
nest?
They are all vertebrates.
proper
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.
Chickens.
common
common and proper
A hen is an adult female chicken.The set of all hens is a subset of the set of all chickens.
It is a proper noun, because it is the name of a specific thing.
common
it's a common noun. a proper noun would be Spider-Man.
Proper