Questions & Answers about Nei, hún lánar músina þeirra.
Why do we use þeirra here instead of a form of sinn?
Why is it músina þeirra (the mouse their) instead of just mús þeirra?
In Icelandic, when you use a possessive word like þeirra after a noun, that noun almost always needs the definite article ("the") attached to it. That is why it is músina (the mouse) and not just mús.
Why does the word for mouse end in -ina (músina)?
mús is a feminine noun. In this sentence, it is the direct object being lent, which means the verb lánar forces it into the accusative case. The -ina ending is the attached definite article ("the") for feminine accusative nouns.
If we wanted to say who she is lending the mouse to, how would that work with lánar?