sentence:
Once I left my phone at home and I couldn’t pay attention to my work at all….According to Cambridge Dictionary Online, once can be both conjugation and adverb. It is obvious that in this case, once is functioning as adverb, but it sounds very contrived to me. So I check the Corpus of Contemporary American English. After reading the first page it is clear to me that once has never been used as an adverb at the beginning of the sentence. I think there must be a grammar rule that says that once can only function as conjugation meaning "as soon as "
Answer
It looks to me like COCA mis-tagged things, seeing as nothing comes up when I try to search with part of speech tagging. Searching, however, for . once , (no PoS but followed by a comma) gets me 2700+ results, almost all of which use “once” as an adverb at the beginning of a sentence. For example:
Once, at Outback, I wanted to order another refill and another margarita, but the waiter ONLY ASKED MY MOM (we were in a party of 4).
Additionally here is an example from Macmillan without a comma (though I would put a comma):
Once we drove all the way to Edinburgh with four little kids in the back seat.
Attribution
Source : Link , Question Author : jxhyc , Answer Author : Laurel
