Breakdown of Verkfræðingurinn þurfti að reikna mikið í grunnskólanum.
mikið
a lot
að
to (infinitive marker)
í
in / into / to (before the hour, in telling time) / per (in frequency expressions)
þurfa
to need
Questions & Answers about Verkfræðingurinn þurfti að reikna mikið í grunnskólanum.
How do we form the past tense for the modal verb þurfa in this sentence?
The verb þurfa (to need to / have to) is irregular. In the simple past tense for the third-person singular ("the engineer"), it becomes þurfti. Notice that it is followed by the infinitive marker að and the main verb, which is reikna (to calculate) here.
How is the long word verkfræðingurinn built?
It is a common Icelandic compound word. It combines verk (work or project) and fræði (science or study). The suffix -ingur makes it a person, giving us verkfræðingur (engineer). The -inn at the very end is the attached definite article meaning "the".
Why does the word for primary school end in -num here?
The base word is grunnskóli. The preposition í (in) triggers the dative case when talking about a fixed location. In the dative case, grunnskóli becomes grunnskóla. When you add the dative definite article for "the", it becomes grunnskólanum.
Why do we use mikið for "a lot" instead of margt?
We use the neuter form mikið (much / a lot) as an adverb here because it describes the uncountable action of calculating. You would use margt (many) if you were talking about a countable number of distinct things.