Breakdown of Það er heimilislegt að sitja hér.
vera
to be
hér
here
það
it / there (existential) / the one (n)
sitja
to sit
Questions & Answers about Það er heimilislegt að sitja hér.
How is the adjective heimilislegt formed from the noun for home?
It comes from the neuter noun heimili (home). To add the productive suffix -legur (meaning -like or -y), the noun is usually put into the genitive case. The genitive of heimili is heimilis, which combines with the suffix to make heimilislegur (home-like or homey).
Why does heimilislegt end in -t here instead of its dictionary form heimilislegur?
Because it must agree with the dummy subject það (it), which is grammatically neuter. When using the pattern 'It is [adjective] to [verb]', the adjective always takes the neuter singular form. The neuter form of the suffix -legur is -legt.
Could I use a word like huggulegt here instead, and how does the meaning differ?
Yes, you could say Það er huggulegt að sitja hér. While huggulegt means cozy or pleasant in a general sense, heimilislegt carries the specific, warm nuance of feeling right at home, even if you are somewhere else like a cafe or a friend's house.
If I wanted to turn this into a question, would I say Er það heimilislegt að sitja hér?