Learn Danish: Jeg har fri i dag. — Nå, det lyder godt. - I am off today.

In Danish, you use the phrase har fri (literally "have free") to say that you are off from work or school. If you translated "I am free" directly as Jeg er fri, it would sound like you were just released from prison or are no longer tied up!

Is i dag always written as two words?

Yes, unlike the English word "today", the Danish i dag is always split into two words. It literally translates to "in day". You will see this pattern in other time expressions too, like i morgen (tomorrow) and i år (this year).

What exactly does Nå mean here?

Nå is a very common Danish filler or reaction word. In this sentence, it translates to "Oh" or "I see". Danes use it all the time to show they are listening or reacting to what you just said.

Why is there a "t" at the end of godt?

The basic word for "good" is god, but here it describes the word det (that). Because det is a neuter word (often called a "t-word" in class), the adjectives describing it must also add a -t at the end. So god becomes godt.