Yes, the words "paper" and "bag" are common nouns. Common nouns are general names for people, places, things, or ideas, and they do not refer to any specific person, place, thing, or idea. In this case, "paper" and "bag" are general names for a material and a container.
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personExamples of common gender nouns are house, school, bag, toy, doll, bird, paper, books, cat, parents, school, and snake.Here is a couple of common gender nouns...StudentPersonParentsChildFriend
Exact nouns for containers can be bag, box, can, jar, bin, etc. Each of these nouns can have exact nouns such a 'bag' for example can be a grocery bag, a school bag, or a laundry bag. In turn, each of these nouns can have an exact noun, for example, a grocery bag can be a plastic grocery bag, a paper grocery bag, a reusable grocery bag, etc.
The common nouns in the sentence are lunch bag and door.Note: The noun 'lunch bag' is an open compound noun, a noun made up of two or more words that form a noun with a meaning of its own.
Collective nouns for confetti are a package or a bag of confetti.
In this context, it is common.
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The Paper Bag Princess was created in 1980.
Paper Bag Records was created in 2002.
The word paper can go before all of them.
The nouns in the sentence are boy, bag, and car.
paper bag