The verbal syntax of English undergoes substantial changes in the Late Middle and Early Modern English periods. The outcome of these changes is a clear division between main verbs and auxiliaries with respect to their syntactic behaviour. On the basis of quantitative data tracing the diachronic development of the distribution of verbal elements with respect to adverbs, this paper argues that the path towards the present-day system with a separate syntactic class of auxiliaries involved several small-scale steps that can be considered to be of the micro- and nano-type in Biberauer & Roberts' (2012, 2016) terminology.