Learn Icelandic: Fresturinn er þann fyrsta maí. - The deadline is on the first of May.

In Icelandic, to say something happens "on the" a certain date, you use the masculine accusative determiner þann followed by an ordinal number (like "first" or "second"). This is the standard pattern for stating exact dates.

The verb here is er (is). Doesn't the verb "to be" usually take the nominative case? Why is þann fyrsta in the accusative?

You are right that vera (to be) usually connects two things in the nominative case. However, þann fyrsta is a time expression telling us exactly when the deadline is. In Icelandic, standalone time expressions that answer "when?" are put in the accusative case, even after the verb "to be".

Why is the word for "first" written as fyrsta instead of the dictionary form fyrsti?

Because it follows the determiner þann, the ordinal number needs to match its case and take a "weak" form. Since þann is in the masculine accusative case, we use the matching weak form fyrsta.

Why isn't the month maí capitalized?

Unlike in English, months of the year, days of the week, and seasons are not capitalized in Icelandic unless they appear at the very beginning of a sentence.

What is the root word for ?