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'.
Not all nouns are the same, though. There are common nouns, and then there are proper nouns, and the difference is very important. In this guide, weâll cover what sorts of words qualify as common nouns, and provide some examples of common nouns to help you separate them from proper nouns.