Irish-English (IrE) as a contact vernacular permits tense, mood and aspect categories to be marked in a manner whichdistinguishes this variety from all other world Englishes. Researchers, however, have been preoccupied with its distinctive tense andaspect markers and much less is known about the manner in which IrE modal relations are expressed. This paper attempts to redressthe imbalance by comparing aspects of modality in IrE and other English varieties and by introducing a morphosyntactic syntagmtermed “modal be+to” which can be used to express both deontic and epistemic modality. The marker isfrequent in Northern Irish Englishes and a detailed account of its use in the South Armagh vernacular is offered here. In addition,attention will be given to locating the potential sources of be+to as the product of a language contactsituation.