Measuring Distance and Time
In English, we often use prepositions to express how far we traveled or how long an action took, such as "We sailed for ten miles" or "We explored for an hour." In Icelandic, you can skip the preposition entirely and simply place the distance or time phrase into the accusative case. This grammar feature is known as the accusative of extent.
To express physical distance, just put the unit of measurement—like a nautical mile (sjómíla) or a kilometer (kílómetri)—in the accusative.
| The submarine sailed ten nautical miles. | Kafbáturinn sigldi tíu sjómílur. |
Duration of Time
The exact same rule applies to time. When you want to say that an action lasted for a specific duration, place the time noun directly into the accusative case.
| We explored the ocean floor for a whole hour. | Við skoðuðum hafsbotninn heila klukkustund. |
Matching Adjectives and Numbers
When you add a descriptive word to your duration or distance—such as the adjective heill (whole) or the number einn (one)—it must match the noun's gender and also take the accusative case.
For a masculine noun like dagur (day) or kílómetri (kilometer), the accusative adjective ends in -an:
| The diver repaired the submarine for a whole day. | Kafarinn lagaði kafbátinn heilan dag. |
For a feminine noun like sjómíla (nautical mile) or klukkustund (hour), the accusative adjective ends in -a:
| I saw the fish swim one nautical mile around the coral reef. | Ég sá fiskinn synda eina sjómílu um kóralrifið. |
For a neuter noun like kvöld (evening), the accusative adjective ends in -t:
| We waited a whole evening in the submarine. | Við biðum heilt kvöld í kafbátnum. |