There appear to be two ways to pronounce the last syllable of the word delphi based on deeply held beliefs and cultural divides and assumptions:
- Phi fi fo fum
IPA /fiː/ using the FLEECE vowel, a monophthong - Fee phi fo fum
IPA /faɪ/ using the PRICE vowel, a phonemic diphthong
I’ve heard that the second of those two ways listed above is the “American” pronunciation, as in the Delphi Automotive motor parts corporation — although that one isn’t how we pronounce it in my office in America, which is probably largely the result of the Russian programmer who introduced us to the Delphi programming language.
I’d say I’d never pronounce the Greek letter “phi” (ϕ, φ) like the English word fee, but I don’t speak Greek and if I did, I would probably pronounce it wrong.
The best answer would go into the history of why Delphi is called Delphi (started as the code name, but caught on) while giving a little Greek lesson (oracle at Delphi) and explaining that there are a lot of non-american Delphi programmers (Marco Cantu calls it Del fee.) It might even touch on motorsports.
Best Answer
I've always said "Dell fee".
In further support of this, the name was chosen (cite) by one of Delphi's developers, Danny Thorpe, who has a decidedly non-Greek name.
If you look into it further, you'll see the name is a reference to the Oracle at Delphi, which was pronounced in ancient Greek as /ðelˈfi/, using the Ancient Greek IPA (/i/ refers to the "hard e" sound, whereas /ai/ would refer to "hard i"). And according to this footnote, "dell fi" is actually the English corruption.