Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Another idea Hopper mentions is that it's an "emergent auxiliary." In effect, that it is grammaticalizing and losing its literal meaning in the process.
Well, Paul Hopper analyzes ‘turn around and’ as an example of hendiadys, a figure of speech used for emphasis. See this link, beginning on p. 154: books.google.co.th/…