Marisa Brook (faculty) has a paper out in Language Variation and Change, 30(2), based on her 2016 doctoral dissertation: "Taking it up a level: Copy-raising and cascaded tiers of morphosyntactic change."
This paper uncovers evidence for two linked levels of morphosyntactic change occurring in Canadian English. The more ordinary is a lexical replacement: with finite subordination after seem, the complementizer like has been overtaking all the alternatives (as if, as though, that, and Ø). On top of this, there is a broader syntactic change whereby the entire finite structure (now represented primarily by like) is beginning to catch on at the expense of infinitival subordination after seem. Drawing on complementary evidence from British English and several partial precedents in the historical linguistics literature, I take this correlation to mean that like has reached sufficient rates among the finite strategy to have instigated the second level of change, to the point that it has ramifications for epistemic and evidential marking with the verb seem. I propose that the best model of these trajectories is a set of increasingly large envelopes of variation, one inside the next, and argue that the envelope might itself be an entity susceptible to change over time.