Conflicting findings are reported for New Englishes and Learner Englishes: similarities are identified mainly on psycholinguistic grounds and differences on sociolinguistic grounds. This article offers an analysis of the progressive form in Black South African English, in which the interaction between gradual increases in proficiency and normative interventions by explicit feedback and editing of published texts is examined to establish the route towards conventionalisation of innovative features. The results indicate that one innovative feature, the extension of the progressive to longer time spans, becomes established as a feature of the variety, but other potential innovations gradually disappear under normative influence and with increased proficiency. Innovations are likely to be accepted if they are insufficiently salient to be targeted for normative correction and sufficiently present in the written and spoken input to become entrenched in the grammatical representations of learners as they turn into advanced users of the New English.