Proper Nouns
We know that a noun is a thing. A proper noun is the name given to that thing. For example "This is my teddy bear Winnie". The first letter in a proper noun is always a capital letter. The name of the teddy is Winnie, so that is the only word that needs to be in capital. A capital letter is also used in the beginning of a sentence but this is not because it is a proper noun.