The interesting this is that I just heard someone on a cooking show say fourth cup, and wonder if it's regional. She's in N. Oklahoma.
I had forgotten about Kool-Aid and Bandaids, but you're right, it's the same here.
I have heard that about all sodas being called cokes, but know that one's regional. We don't use that here, but it is a very interesting usage. I'd love to know how it started and 'took' in one place, but not another.
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