Is Arkitekt pronounced with a tj-ljud or twice with k? In other recordings on Duolingo I heard it pronounced like Ark-itekt.
Both ways work. I guess most people say it with a tj sound, but the pronunciation with a k sound is favored by some, especially by some architects, so it's the more prestigious pronunciation.
Wouldn't "skriver brev" work too? Someone said in an earlier discussion that certain words like "ha fest" come together and don't require the article. (In this cases, "skriva brev").
Yes, that would be a valid sentence if you’re mostly focusing on the action of writing a letter rather than the product or the number of letters s/he’s writing.
The verb "skriver" is easy to remind for me because it's very similar to "write" in spanish :) (Escribir)