Þér megið sitja þar inni.

there

Breakdown of Þér megið sitja þar inni.

• mega: to be allowed
• sitja: to sit
• þér: you (polite)

Questions & Answers about Þér megið sitja þar inni.

What does Þér mean here, and why not use þú or þið?

Þér is the old/formal way to address one person politely (like German Sie). It takes plural verb agreement. In modern Icelandic, this is rare; people normally use:

• Singular informal: þú
• Plural: þið

So everyday speech would more likely say: Þú mátt sitja þar inni (1 person) or Þið megið sitja þar inni (several people).

Is Þér singular or plural in this sentence?

Singular, but formal. It uses plural verb forms by convention: Þér megið… to one person. If you are talking to several people, use þið megið….

Isn’t þér the dative of þú? How can it be a subject here?

Yes, þér (lowercase) is the dative singular of þú (e.g., Ég hjálpa þér = I help you). But in this sentence, Þér is a special nominative form used for formal address. Context tells you which function is intended:

• Object dative: Ég gef þér bók (I give you a book).
• Formal subject: Þér megið… (You may…).

Why megið and not mátt?