Questions & Answers about Meðferðin er mikilvæg.
- meðferð = treatment
- -in = the definite article, meaning the
So meðferðin means the treatment.
This is very common in Icelandic: instead of using a separate word like English the, Icelandic usually adds the article to the end of the noun.
- meðferð = treatment
- meðferðin = the treatment
In normal Icelandic, the definite article is usually a suffix, so it gets attached to the noun.
That means:
There is also a separate form like hinn / hin / hið, but that is used much less often and usually in more formal, literary, or special grammatical contexts.
So for everyday Icelandic, meðferðin is the natural form.