Learn Farsi: فردا یکشنبه است.

In Farsi, the verb almost always goes at the very end of the sentence. So instead of saying 'Tomorrow is Sunday' like in English, the structure is literally 'Tomorrow Sunday is'.

How does the word yekshanbeh translate literally?

It literally means 'day one' or 'one-Saturday'. In the Iranian calendar, the week starts on Saturday, which is called shanbeh. Sunday is the first day after that, so it is made by combining yek (one) and shanbeh.

How would this be pronounced in everyday casual conversation?

In casual spoken Farsi, the formal verb ast is usually shortened. Because yekshanbeh ends in an 'eh' vowel sound, the verb shrinks down to just an 's' sound attached to the end. You will usually hear people say yekshanbeh-s instead of the full yekshanbeh ast.

Are days of the week capitalized in Farsi?

No, the Farsi alphabet does not have capital and lowercase letters. A word like yekshanbeh looks exactly the same whether it is in the middle of a sentence or at the very beginning.