"He is a writer."
Translation:Lui è uno scrittore.
In Italian there is no distinction between a and one :) Here, you see uno because of the first few letters in scrittore... when you see s + consonant(s), use uno!
The grammar books tell you that you should not use an indefinite article to say what someone's job is. My "è scrittore" was not accepted. I think this is a bug, here's the "correct" answer DL gave me: "È 1 scrittore." Now that definitely looks much better.....I've reported it all the same.