Questions & Answers about Ég er nýbúinn að klára erindið.
Why does the sentence use both nýbúinn and klára if they both relate to finishing?
The phrase vera nýbúinn að is a fixed grammar structure used to express that you have 'just done' something. While klára is the actual action you performed (finishing the errand), nýbúinn að acts as a time marker. Even though it literally means 'newly finished to', to Icelandic speakers it just means 'I have recently...'.
Does the word nýbúinn change if a woman is speaking?
Yes, it does. In this structure, the búinn part acts like an adjective describing the subject, so it must agree in gender and number. The form nýbúinn tells us the speaker is male. A female speaker would drop one 'n' and say Ég er nýbúin.
What case is erindið in?
It is in the accusative case because it is the direct object of the verb klára. For neuter nouns like erindi, the accusative form is identical to the nominative form. Note that if you used the synonym ljúka (to finish) instead of klára, the noun would need to be in the dative case instead.
Why does the definite article look like -ð instead of -ið on erindið?