> It's again, unofficial and unwritten and unstudied American English.
Hm? Where'd you get that impression?
It's certainly unofficial -- English has no official governing body, so essentially _all_ English is unofficial. However, zero-derived denominal verbs are quite common in even formal written English [0], are well studied [1], and aren't at all limited to American English [2].
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[0] As seen in this very thread.
[1] It took me almost no time to find a random academic paper [1a] and two Wikipedia articles [1b][1c].
Hm? Where'd you get that impression?
It's certainly unofficial -- English has no official governing body, so essentially _all_ English is unofficial. However, zero-derived denominal verbs are quite common in even formal written English [0], are well studied [1], and aren't at all limited to American English [2].
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[0] As seen in this very thread.
[1] It took me almost no time to find a random academic paper [1a] and two Wikipedia articles [1b][1c].
[1a] https://dingo.sbs.arizona.edu/~hharley/PDFs/HarleyDenominalV...
[1b] https://en.wikipedia.org/wiki/Denominal_verb
[1c] https://en.wikipedia.org/wiki/Conversion_(word_formation)
[2] https://www.thetimes.com/uk/politics/article/the-pedant-noun...