Breakdown of Vilt þú þvo skyrtuna þína?
þú
you
vilja
to want (to will, be willing)
þinn
your (m, f, n: þinn, þín, þitt)
þvo
to wash
Questions & Answers about Vilt þú þvo skyrtuna þína?
Why is the word for "your" þína here instead of þinn?
The possessive pronoun has to match the noun it belongs to in gender, number, and case. The noun here is skyrtuna (the shirt), which is a feminine word in the accusative case. The feminine, accusative singular form of þinn is þína.
Why does it say skyrtuna þína instead of putting the word for "your" before the noun?
In Icelandic, it is much more natural to put the possessive word after the noun. When you do this, the noun almost always takes the definite article (the attached "the"). So instead of saying "your shirt", Icelandic says "the-shirt your" (skyrtuna þína).
What causes skyrtuna (the shirt) to be in the accusative case?
It is the direct object of the verb þvo (to wash) — meaning it is the thing that is being washed. Direct objects in Icelandic usually take the accusative case. Since the base word skyrta is feminine, its definite accusative form becomes skyrtuna.
Why is þvo (to wash) in its dictionary form instead of being conjugated?
The primary verb in this sentence is vilja (to want), which is conjugated as vilt to match þú (you). When you have a helper verb like "want" followed by another action, the second verb stays in its infinitive (dictionary) form, just like in English when we say "want to wash".