I'm curious as to why some of the labial initials are followed with -eng and others with -ong when they all have the same rhyme (whether the speaker rhymes them with "teng" or not). I wonder the same about "ben" "pen" "men" "fen" and "wun". This seems an inconsistency with the way Standard Mandarin is pronounced in Taiwan. Those with heavy Taiwanese accents (as opposed to Standard Mandarin) would say "wun" or even "?wun" (? being a glottal stop), but the same people would say "hun" instead of "fen". { }