Learn Icelandic: Sækið töskuna mína!

The verb sækja (to fetch) has the -ið ending here, making it sækið. In Icelandic, adding -ið to the stem of a verb creates an affirmative plural command, meaning you are telling two or more people to do the action.

Why is the word for bag töskuna instead of taska?

The bag is the direct object being fetched, so it must be in the accusative case. The basic feminine noun taska (a bag) changes to tösku in the accusative. When you add the definite article to mean the bag, it becomes töskuna.

Why is the word for my mína here?

Possessive words have to match the noun they describe. Because töskuna is a feminine, singular noun in the accusative case, the basic word for my (minn) must also take its feminine accusative singular form, which is mína.

Why does mína come after the noun instead of before it?

In Icelandic, possessive words like my or your usually come immediately after the noun. When this happens, the noun generally takes the definite article (the suffix at the end). So töskuna mína literally translates word-for-word as the bag my.