Breakdown of Hann ákvað að verða verkfræðingur af því að hann vildi byggja hús.
húsið
the house
hann
he
að
to (infinitive marker)
vilja
to want (to will, be willing)
Questions & Answers about Hann ákvað að verða verkfræðingur af því að hann vildi byggja hús.
Why is there no að (to) before byggja?
Because vildi is a modal verb. Just like in earlier lessons with present tense modals, the past tense form vildi (wanted) is followed directly by the infinitive of the main verb (byggja) without needing the word að in between.
What is the infinitive of vildi and how does it form the past tense?
Vildi is the simple past tense of vilja (to want). Its present tense form is vill (wants). Like several other modal verbs, it has a slight vowel change from the infinitive, ending in -di for the past tense.
Why is verkfræðingur in the nominative case instead of the accusative?
Because of the verb verða (to become). Just like the verb vera (to be), verða links the subject to a description of itself. Therefore, the noun that follows it stays in the nominative case rather than taking an object case.
Why does the sentence use three words (af því að) for "because"?
In Icelandic, af því að is the standard, most common way to say "because". It literally translates to "of that that", but you should memorize it as a single chunk. You will use this exact phrase all the time to give reasons.