Proper nouns are names for a specific person, place or thing. The word city is a common noun, but Provo is a specific city. Provo is a proper noun. The same rule applies for things. When you go out for dinner you can order a soda, or you could order a Coke. Coke is a proper noun for a type of soda.
It is important to learn as many nouns as you can. The more nouns you know the better your English will become. Follow us on twitter as we will be posting more about nouns all week!