Hello, I was watching an episode of the 1950s TV show "To Tell the Truth" today. They often use speech patterns/structure/vocabulary which are not often heard nowadays. << YouTube link removed. >> One of the panelists asks the question (not necessarily word for word): "Are you sure that one of you are this girl?". The TV host then repeats the question with the same verb conjugation. I am curious: has anyone heard/seen this structure in use before? Has it traditionally been seen as correct? I would normally have considered this incorrect, but I am wondering whether this structure is an acceptable (although perhaps dated and less logical) equivalent to "one of you is"? (it also reminds me of the grammar conversation on "What's My Line" about saying "at my left" instead of "on my left"--once again, a structure I have only heard on television) Thank you in advance!