SlexAxton/messageformat.js — pull request #40 by osk (2014-03-10 23:39:53+00:00)
Title: More nuanced pluralization for Icelandic

When pluralizing in Icelandic words take singular form if the counter ends in 1, except for 11, e.g.:
1 hestur, 2 hestar, ..., 11 hestar, ..., 20 hestar, 21 hestur
unable to find a source for this online.