The interplay of four standard languages and a number of spoken languages makes Malaysia an interesting case of societal multilingualism. There is extensive convergence between the spoken varieties. ‘Malaysian English’ (ME) has developed its own structures which can be shown to copy structures of the mother tongues of the speakers at all levels of grammar, thereby being an example for localisation and the creation of a new dialect/sociolect. An analysis of the basilectal register of ME in ethnic Chinese speakers finds that converging patterns of ME and Malaysian (Chinese) languages, with situational lexical borrowing between the various languages. Sociolinguistically, ME plays the same role as any dialect, with covert prestige as an ingroup (identity) marker which is avoided in acrolectal (outgroup) communication. Spoken English in Malaysia can therefore be seen as a localised creoloid dialect of English, based on linguistic substrates. Sociolinguistically, ME is mainly an orate register for basilectal and mesolectal intra-group communication.