"My hat is there."
Translation:Il mio cappello è là.
As a general rule, lì refers to something that's close to you, and là refers to something that's farther away. Kind of like "there" and "over there." Source: My husband is a native Italian speaker.
Technically, lì indicates a more specific area than là; but nowadays they're used interchangeably.
At times il or la is used before mio or mia and at other times it's incorrect to use il or la. Is there a rule?
Glad you asked. Your answer can be found in detail with great examples in this link. #1 answers your question, and #2 answers when even the possessive adjective can be omitted itself!
why can't i say "mio cappello è là", i'm confused about when you can use or omit the article.
I thought the article wasn't necessary when speaking about personal clothing items?
It's best to be grammatically correct, but if one were conversing in Italian it would still be understood what is being said even if the article is omitted in conversation.