Questions & Answers about Det är en hund.
Since hund is an en-word, shouldn't it be den är instead of det är?
When we introduce or point out a new thing by saying 'It is...' or 'That is...', Swedish always uses the fixed phrase det är. This rule applies regardless of whether the noun following it is an en-word or an ett-word. You only use den if you are describing a specific dog you already mentioned (for example, den är brun meaning 'it is brown').
How do I know whether to use en or ett before hund?
In Swedish, every noun belongs to one of two grammatical groups: en-words or ett-words. Hund is an en-word, so it takes the indefinite article en (meaning 'a' or 'an'). Because there is no simple rule for guessing which group a noun belongs to, it is a great habit to memorize the article right along with the noun when you learn it: en hund.
If I wanted to say 'I am a dog' or 'You are a dog', would the verb är change?
No, it wouldn't! Unlike English, which changes the verb depending on the person (I am, you are, it is), Swedish verbs stay exactly the same for everyone. You use är across the board: jag är (I am), du är (you are), and det är (that is).