Morphosyntactic Tagging of Old Icelandic Texts and Its Use in Studying Syntactic Variation and Change

We describe experiments with morphosyntactic tagging of Old Icelandic (Old Norse) narrative texts using different tagging models for the TnT tagger [3] and a tagset of almost 700 tags, originally developed for Modern Icelandic. It is shown that by using a model that has been trained on both Old and Modern Icelandic texts, we can get 92.7% tagging accuracy which is considerably better than the 90.4% that have been reported for Modern Icelandic. Although our tagging is morphological in nature, the tags carry a substantial amount of syntactic information and the tagging is detailed enough for the syntactic function of words to be more or less deduced from their morphology and the adjacent words. We show that the morphosyntactic tags can be very useful in locating certain syntactic constructions and features in a large corpus of Old Icelandic narrative texts. We demonstrate this by searching for—and finding—previously undiscovered examples of a number of syntactic constructions in the corpus.We conclude that in a highly inflectional language, a morphologically tagged corpus can be an important tool in studying syntactic variation and change, in the absence of a fully parsed corpus which of course gives more possibilities.