The caffeine content of coffee varies greatly, depending on the beans, how they're roasted, and other factors, but the average for an 8-ounce cup is about 100 milligrams (mg).
No, 'cat' is a common noun, a word for any cat of any kind. A proper noun is the name of a person, a place, a thing, or a title; for example: Cat Deeley, host of TV series 'So You Think You Can Dance'.
A proper noun or adjective is a proper nameâit designates a particular person, place, or thing. In sentence 1 above, we capitalize New York City and East River because they are proper nouns. Both are geographical place names. A common noun or adjective, in contrast, is a generic labelâit designates a general type of person, place, or thing.