Questions & Answers about Mannen är spanjor och konsult här.
Why isn't there an en before spanjor and konsult?
In Swedish, when you state someone's profession, nationality, or affiliation after the verb är (is), you drop the indefinite article (en or ett). Since he is a Spaniard (nationality) and a consultant (profession), Swedish just says he is spanjor and konsult.
Would I still leave out the article if I added an adjective, like "a successful consultant"?
No, if you add a descriptive adjective before the profession or nationality, the article comes back. For example, "He is a successful consultant" translates to Han är en framgångsrik konsult. The zero-article rule only applies to the bare noun.
I know the country is Spanien, so is spanjor only used for people?
Yes, spanjor refers specifically to a Spanish person (traditionally a male, or as a general term for a Spaniard). The country is Spanien, and the language or the adjective "Spanish" is spansk or spanska.
What if I said Mannen är en spanjor instead? Would a Swede understand me?
They would understand you perfectly, but it sounds unnatural. Adding the article to a bare nationality or profession sounds like you are emphasizing them as a specific object or instance of a category, rather than just describing their identity.