Old Irish is the language of Ireland in the period from the 8th to the 10th century AD, and is the oldest Celtic language well enough attested for adequate grammatical study. The book provides the only available detailed linguistic analysis of the syntactic structure of the Old Irish sentence. The approach is functional and typological, on the basis of a text corpus from the glosses on the Pauline epistles at Würzburg, with further material from Old Irish legal texts. The emphasis is on the communicative content and intent of the sentences of the corpus.