Learn Icelandic: Ég misskildi skilaboðin, fyrirgefðu. - I misunderstood the message, sorry.

The prefix mis- works exactly like the English prefix "mis-", showing that an action was done incorrectly. When attached to skilja (to understand), it forms misskilja (to misunderstand). Here we see it conjugated in the first-person past tense as misskildi.

Why does skilaboðin end in -in?

The word for message is skilaboð, which is a neuter noun that is frequently used in the plural form even when referring to a single message in English. The -in at the end is the attached definite article for the neuter plural accusative case, turning "message" into "the message".

Are the words misskildi and skilaboðin related?

Yes, both share the root skil. While skilja means to understand, skilaboð is a compound of skil (understanding or return) and boð (message or offer). So skilaboð essentially means a message that conveys an understanding or information.

How does the word fyrirgefðu break down grammatically?

It comes from the verb fyrirgefa (to forgive). The word is in the imperative (command) form, and the -ðu suffix is the attached pronoun þú (you). Literally meaning "forgive, you", it is the most common way to say "sorry" or "excuse me" in Icelandic.