The thesis presents a corpus based empirical analysis of the language used in SMS text messaging in Pakistan. The study is descriptive in nature and examines types, causes, and patterns/principles of various linguistic adaptations made in text messages. It also provides historical insights, and discusses linguistic-cum-educational impacts and implications of these adaptations. Primarily, the study is based on the linguistic analysis of an SMS corpus of 5000 interpersonal text messages collected from Pakistani texters. For triangulation purposes, it also examines the metalinguistic perceptions of 500 texters who also provided their personal text messages for the study. The study explores linguistic adaptations in six major categories, i.e. lexical, syntactic, punctuation, space, code, and script adaptations in text messages. It was found in the study that linguistic adaptations in text messages are mostly made under certain principles/patterns. Most intentional adaptations in text messages are caused by three major factors that are to be economical in the use of time and effort, to be creative/innovative in developing new language patterns, and to be rapid in SMS communication. Some unintentional adaptations are caused by the careless attitude or poor language command of texters. In addition, many punctuation adaptations are specifically made for paralinguistic purposes. Code alterations are made in the bilingual settings of texters. Lastly, the Roman script is preferred because most Pakistani texters are not adept in typing the Arabic/Urdu script, and so they use the Roman script for both Urdu and English. In the historical perspective, these adaptations are not completely new in nature because their traces are found in history or in other modes of communication. Moreover, these adaptations have various linguistic/educational impacts, and these impacts lead to certain implications for the conventional standards of languages and their teaching.