Questions & Answers about Glasið brotnar, því það er gamalt.
-ið is the definite article attached to the noun (Icelandic usually attaches “the” to the end of the word).
So glas = a glass, and glasið = the glass (neuter, singular, nominative/accusative).
Because in Glasið brotnar, the glass is the subject of the sentence, so it’s in the nominative case.
A quick case overview for glas:
- Nominative: (hið) glas / definite glasið
- Accusative: glas / glasið
- Dative: glasi / glasinu
- Genitive: glass / glassins
Here you need nominative → Glasið.