Dip-thong

[Dfcoye at AOL.COM]

I think 95% of Americans would say  dip-theria, and the vast majority who
were aware of the word would say DIP-thong.   In grad school one of our
professors was adamant that we all say DIFF-thong, but there is a
counter-argument for /p/.  Granted ph- is almost always /f/, but in English
there are (I think!) no instances of native words with the /f/-theta
combination, so whenver a Greek word with this combination was introduced, we
rendered it more speakable by making that /f/ a /p/.    The earliest OED
entry for 'diphthong/ (1400s) indicates not only a /p/ but also a /t/
--diptong.  The spelling 'dipthong' is shown as early as the 17th c.  There
is also the Old Testament foolish father Jephtha (mentioned in Hamlet),
where spellings indicate it too was JEP-thuh.   Compare also those unpleasant
sores of the mouth "aphtha'" which the few doctors I have heard pronounce it
render as 'AP thuh'.

Dale Coye
The College of NJ