What's the difference between common and proper nouns?

Question

Proper nouns are used in formal writing but common nouns are used in speaking.

Proper nouns are specific and capitalized. Common nouns are general and not capitalized.

There is no difference - these are the same thing.

Common nouns are everywhere and proper nouns are more rare.

Answer 1

The correct answer is:

Proper nouns are specific and capitalized, while common nouns are general and not capitalized.