If you mean a regular plural noun as opposed to an irregular plural noun, then the answer is that a common noun can be a regular plural or an irregular plural; and a proper noun can be either a regular plural or an irregular plural. The difference between how a regular and an irregular plural noun is formed is usually based on the origin language from which it came to the English language.
A common noun is a word for any person, place, thing, or idea.
A proper is the name of a specific person, place, thing, or a title.
The regular plurals are formed by adding an 's' or an 'es' to the end of the singular noun to make it a plural noun. The irregular plurals are quite varied. See the link below for a simple step by step list for using irregular plurals.
Radio is not a common noun, it is a regular noun.
The word factory is a common noun - it does not need a capital letter in regular cases.
No. Regular is a noun or an adjective (common, usual). The adverb is "regularly."
The word meatballs is a plural concrete common noun with a regular plural (because the plural ends with -s.)
The word church is a singular, common, concrete noun. The plural form is churches, a regular plural (a regular plural is a noun made plural by adding 's' or 'es' to the end of the word; an irregular plural is a noun that is made plural in some other way).
No, the word "iceberg" is a common noun, as it refers to a general type of large floating mass of ice. It is not a specific or unique entity that would require capitalization as a proper noun.
The noun 'job' is a singular, common, abstract noun; a word for a paid position of regular employment; a task or piece of work.
NO. It would only be a proper noun if there was the name of the street before it. EX: 9th avenue, or Hickory Avenue. Then it would be a proper noun. When alone, it is a regular noun.
Yes, the noun 'boarders' is a common noun, a general word for someone or something whose regular meals or meals and lodging are regularly paid for; or a person who rides a snowboard or surfboard.
It can be, in context. If referring to an individual bird, then it is a regular common noun. If it is talking about chicken meat, then this is an uncountable noun, there is no 'a chicken' when talking about chicken meat.
No it's just a regular noun put in the category of person.
Oh, dude, tomorrow is like totally a common noun. It's like, you know, just a regular ol' word we use to talk about the day after today. So yeah, tomorrow is totally a common noun, like no big deal.