Wong, Jock (2008). Anglo English and Singapore English tags: Their meanings and cultural significance. Pragmatics & Cognition, 16(1), 88-117. DOI: 10.1075/p&c.16.1.06won

A more recent publication building on this one is chapter 6 (pp. 180-229) of:

Wong, Jock O. (2014). The culture of Singapore English. Cambridge: Cambridge University Press. DOI: 10.1017/CBO9781139519519

This study investigates a few Anglo English and Singapore English tags. The focus is on their meaning and the ways of thinking they reflect, rather than their forms and functions. The study contrasts the so-called Anglo English tag questions and the Singapore English tag is it? and tries to show that their semantic and pragmatic differences relate to differences in ways of thinking in the two cultures. For the purposes of this research, meaning is articulated in a paraphrase couched in Natural Semantic Metalanguage (NSM), which comprises a set of empirically established semantic primes and a universal grammar.