There are 70 to 80 different consonant sounds in use in languages around the world, but each language uses only a subset 0f these to pronounce its words. Each language thus needs only a subset of written consonants to spell its words phonetically. But what do they use to pronounce or spell foreign words that use other consonants?
The sounds of various consonants in English can be tabulated in various ways. Here is one way:
Voiced / Unvoiced B / P D / T G / K V / F J / CH Z / S THis / THing ZH / SH as in measure / pressure
When you pronounce voiced consonants, you are actually “humming” a bit; that’s the “voice”. The consonants M and N are also voiced, but they do not have unvoiced partners. Notice also that B, P, D, and T produce quick little puffs of air; these are termed “plosives”.
As it happens, although Greek has the letters beta and delta, these are not pronounced like our B and D, but rather more like V and the TH in “this”. Then how do the Greeks spell the English word “beer”? They spell it (in Greek letters, of course) “mpeer”. This combines the effect of a voice and the proper plosive. Similarly, the English name “Donna” is spelled “Ntonna”.
In the same vein, we know that the letter phi in Ancient Greek was pronounced p-h. That is, the word “phillip” was pronounced more like “p-hillip”. Alexander the Great’s brother Phillip was the temporary regent of Egypt after it was conquered by Alexander. In writing the name in hieroglyphs, the Egyptians used their symbols for P and H, even though Egyptian had an F. Therefore, the name was pronounced “p-hillip”, not “fillip”.