The thesis investigates the loss of MID in English through quantitative methods using
historical corpus data. The research covers the period from the 10th century (the late Old
English period) to the 14th century when MID became extinct in most Middle English
literature. With the help of logistic regression analysis, the origin of the loss was identified in
the 12th-century East Midlands due to the intense Anglo-Scandinavian contact. Language
shift and dialect mixing may have occurred in the historical Anglo-Scandinavian community,
leading to the semantic gain of WIÐ (originally an oppositional preposition) and a linguistic
bias against MID. Detailed textual discussions of MID and WIÐ were made on the late Old
English period and on each Middle English dialectal region. Multiple sociolinguistic factors
such as immigrant society, the class of free peasantry, style and register concern are also
involved in the historical change
