"A green jacket."
Translation:Una chaqueta verde.
But that literally translates to "a jacket of green", which doesn't make much sense because it is green not of it. For example, "una tienda de ropa" works because it is literally a store of clothing (for/containing clothes). I don't know how accurate this is, but I figured I could learn a little too by explaining what I think I know.
Está and es both mean is. So what's the difference? If you want to say where someone or something is located, use está. You also use está when you're talking about something that's only temporarily true.
Meanwhile, es is used to describe the qualities of a person or thing.
(c) Duolingo tips for the "travel" lesson.
Yes, it's pretty simple. You use de to connect two nouns. Pescado is a noun, so it cannot directly describe another noun. That's also why you see un restaurante español / a Spanish restaurant, which is Spanish (of or relating to Spain), but un libro de Español / a Spanish book, which is a book about the Spanish language.