Days of the Week
In Icelandic, all days of the week end in -dagur (day). When talking about when things happen, you will use the preposition á (on). However, the grammatical case changes depending on whether you are talking about a single, specific day or a recurring weekly routine.
Specific Days: á + Accusative
To say you are doing something "on Monday" (meaning this coming Monday or one specific Monday), use á followed by the accusative case with the definite article attached.
For words ending in -dagur, the accusative definite form is -daginn.
| I work on Monday. | Ég vinn á mánudaginn. |
| He is coming on Tuesday. | Hann kemur á þriðjudaginn. |
| I need to work on Wednesday. | Ég þarf að vinna á miðvikudaginn. |
Recurring Routines: á + Dative
To say you do something "on Mondays" (meaning as a habit, every week), use á followed by the dative plural form.
For words ending in -dagur, the dative plural is -dögum. Notice how the a changes to ö—this is a very common vowel shift in Icelandic triggered by the -um plural ending.
| We always work on Mondays. | Við vinnum alltaf á mánudögum. |
| I find the food bad on Tuesdays. | Mér finnst maturinn vondur á þriðjudögum. |
| I always go to the gym on Thursdays. | Ég fer alltaf í ræktina á fimmtudögum. |
Side by Side
Pay attention to the ending to know if someone is talking about a one-time event or a regular habit. Compare these two sentences about Friday (föstudagur):
| The party is on Friday. | Veislan er á föstudaginn. |
| We order pizza on Fridays. | Við pöntum pitsu á föstudögum. |
