The Dative of Temporal Difference
When you want to describe an event happening a certain amount of time before or after another—like "two weeks later" or "three years earlier"—Icelandic pairs a time adverb with a noun phrase in the dative case.
The most common adverbs for this are fyrr (earlier) and síðar (later). The time amount that precedes the adverb must be in the dative case. This structure is very useful when discussing the slow, deliberate timeline of cultivating a bonsai tree.
| I pruned this dwarf tree three years earlier. | Ég klippti þetta dvergtré þremur árum fyrr. |
| Two weeks later she chose a good fertilizer. | Tveimur vikum síðar valdi hún góðan áburð. |
Synonyms: áður and seinna
You will also frequently see áður used for "earlier" and seinna for "later". These function exactly the same way, requiring the time difference to be in the dative case.
Notice how the numbers 1-4 decline to match the gender and case of the time unit.
| One month later the teacher repotted the tree in order to enlarge the trunk. | Einum mánuði seinna umplantaði kennarinn trénu til þess að stækka stofninn. |
| Ten weeks earlier the gardener gave the bud a strong fertilizer in order to help the tree. | Tíu vikum áður gaf garðyrkjumaðurinn bruminu sterkan áburð til þess að hjálpa trénu. |
Doing Something "For Days on End"
To emphasize that an action continued for a prolonged, unbroken period of time, Icelandic uses the word saman directly after a time unit. The time unit itself is always in the dative plural.
This allows you to create phrases like dögum saman (for days on end) or klukkutímum saman (for hours on end).
| We examined the young bud and the thick trunk for hours on end. | Við skoðuðum unga brumið og þykka stofninn klukkutímum saman. |
| He used the pruning shears for days on end in order to fix a new tree branch. | Hann notaði klippurnar dögum saman til þess að laga nýja trjágrein. |
You can easily combine both of these dative time structures in the same sentence to clearly describe a timeline of events.
| Four days earlier he examined the tree branch and the pruning shears for hours on end. | Fjórum dögum áður skoðaði hann trjágreinina og klippurnar klukkutímum saman. |