In British English, we pronounce the word 'progress' as pro—gress.
Whereas in American English it's pronounced as prog—ress.
So how would Americans pronounce the word 'progression'?
It sounds wrong to me to be pronounced as anything other than pro—gresh—on.
Best Answer
You are correct that, in the US, progression is pronounced with pro- as the first syllable, not prog-.
But the most significant shift is the emphasis being placed on the second rather than the first syllable. Many in the US would still pronounce the o in the first syllable with a shorter sound, like a schwa, rather than a true long o.