Breakdown of Vörðurinn var ekki að horfa á sjónvarpið.
vera
to be
ekki
not
að
to (infinitive marker)
horfa
to watch
Questions & Answers about Vörðurinn var ekki að horfa á sjónvarpið.
Where does ekki (not) go when using the past continuous tense?
In continuous sentences, ekki goes right after the conjugated verb (var) and before the að + infinitive part. So the structure is always: conjugated verb + ekki + að + infinitive verb.
Why do we need the preposition á before sjónvarpið?
The verb horfa translates closer to the English word "look", so it requires the preposition á (at/on) to show what you are looking at. While English says "watch TV", Icelandic says horfa á (look at TV).
Why is sjónvarpið in the accusative case here?
The preposition á forces the following noun into the accusative case when it involves directing your gaze toward something. Because sjónvarp (television) is a neuter noun, its accusative form looks exactly the same as its base dictionary form, and the -ið at the end simply means "the".
What is the base dictionary form of Vörðurinn?
The base word is vörður, which is a masculine noun meaning "guard". The -inn at the end is the attached definite article, making it "the guard".