From George Orwell's 1984, part 2 chapter 9:
For if leisure and security were enjoyed by all alike, the great mass of human beings who are normally stupefied by poverty would become literate and would learn to think for themselves; and when once they had done this, they would sooner or later realize that the privileged minority had no function, and they would sweep it away.
It seems like either the "when" or the "once" is unnecessary. Has a feel of Britishness to it (the book is from the UK).
Is this officially correct? If so, how does it work grammatically?
Best Answer
I don't think it's pleonastic, though it might well be obsolescent. I think once can still be read as an adverb here: "when they had done this even once".
I'm guessing that this construction when once is what led to once being reanalysed as a conjunction.