This thesis is a sociolinguistic investigation into the variable encoding by form of the discourse variables 'I don't know', 'I don't think' and negative polarity tag questions within a variety of English spoken in the north-east of England. Combining qualitative methods from conversation analysis and quantitative methods from variationist socioloinguistics, it examines the pragmatic functions the variables perform and explores whether their surface realisations correlate with their functions and with the broad social dimensions of age and gender. Qualitative analysis shows that the selected discourse variables perform multiple functions in the interpersonal and textual domains of discourse. The quantitative analysis demonstrates that pragmatic and social factors are strongly implicated in the variation in the form of these variables, although the extent of their impact differs according to the geographical distribution of the variants involved. The occurrence of non-localisable and supra-local discourse variants, which have relatively wide geographical spreads, is strongly conditioned by discourse function.  The impact on their distribution of social factors is generally less important than that of function. Conversely, localised variants, whose usage is less widespread, do not display function-specific patterning. Their occurrence is highly constrained by social factors.  The variables’ multifunctionality and, to an extent, their variants’ functional distributions are attributed to processes involved in grammaticalisation, including semantic bleaching, pragmatic strengthening, phonetic attrition and decategorialisation. The study demonstrates that discourse variants, like variants in other components of language, are not randomly distributed in speech but display systematic patterning along multiple contextual factors.

Thesis (Ph. D.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 273-309).

Thesis (Ph. D.)--University of Pennsylvania, 1979. / Includes bibliographical references (leaves 215-222). Also issued in print.

Thesis (Ph. D.)--University of Pennsylvania, 1979. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 215-222).

Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on July 14, 2009). Includes bibliographical references.

Thesis (MA)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (M.A.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 97-100.

Thesis (M.A.)--West Virginia University, 1998. / Title from document title page. Document formatted into pages; contains iii, 68 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 64-68).

Thesis (Ph. D.)--University of Wisconsin--Madison, 2000. / Includes bibliographical references (p. 279-292). Also available on the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 2000. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 279-292).