A powerful discourse-pragmatic agent of grammatical change in English since the mid-twentieth century has been the increasing acceptance of colloquialism. Little is known, however, about its influence on grammatical developments in regional varieties of World English other than the two inner circle ‘supervarieties’, British and American English. This paper reports findings from a corpus-based study of three grammatical categories known to be undergoing a colloquialism-related rise in contemporary English, across a range of registers in ten World Englishes: quasi-modals (have to, have got to, be going to, want to), get-passives, and first person plural inclusive let’s. In each case comparisons are drawn with non-colloquial variants: modals (must, should, will, shall), be-passives, and let us. Subsequent functional interpretation of the data is used to explore the effect upon the quantitative patterns identified of the phenomenon of colloquialism and of further factors with which it interacts (including Americanism, prescriptivism, and evolutionary status).