Breakdown of Þú þarft passann þinn í dag.
þú
you
í dag
today
þurfa
to need
þinn
your (m, f, n: þinn, þín, þitt)
Questions & Answers about Þú þarft passann þinn í dag.
Why do we say passann þinn (the passport your) instead of just passa þinn?
In Icelandic, when you use a possessive pronoun like þinn (your) right after a noun, that noun usually has the definite article attached to it. That is why we say passann þinn (literally: the passport your).
I thought the verb þurfa (to need) makes the object accusative. Why does þinn look like it is in the nominative (subject) form?
You are right that þurfa forces its object into the accusative case! The trick here is that for masculine singular words like passi (passport), the accusative form of þinn happens to be exactly the same as the nominative form: þinn. If the word were feminine, it would change to þína.
How do we get passann from the dictionary word for passport?
The dictionary word is passi (a masculine noun). Because it is the direct object of what you need, it changes to the accusative case: passa. Then, because we need to say the passport to use the possessive pronoun, we add the masculine accusative definite ending -nn, making it passann.
Does í dag always mean 'today'?
Yes! Literally it means 'in day', but it is the standard everyday Icelandic phrase for 'today'. Just like in English, time phrases like this usually go at the end of the sentence.