How to pronounce Greek letters in English
The Greek alphabet is used in many fields, including science (mostly physics and mathematics, where one often runs out of letters to use in equations), finance, and technology. Some of you may even use it on a post card from your holiday in Greece. Once you are able to write and correctly identify a given Greek letter, you may find yourself wondering what the commonly used pronunciation of Greek letters in English is. German readers will find that the latter often differs from the German pronunciation, although many people feel that it is perfectly OK to use the Greek pronunciation in English (see the comments by David). The importance of knowing the Greek alphabet as a scientist is also pointed out by Nobel Laureate Gerald ‘t Hooft, see here.
Below, I have compiled the correct pronunciations and some frequently heard incorrect pronunciations for each letter. Since the pronunciation is the same for upper and lower case letters, I have only listed the latter. Remarkably, the Oxford Advanced Learner’s Dictionary provides an entry for each letter, including audio files for their pronunciation. In addition, I have included pronunciations which are given in the Longman Pronunciation Dictionary.
In the table, the British and American pronunciations are separated by a vertical bar (|), with the British variant(s) given first. Note that in many American accents, the letter t is replaced by a softened sound similar to d (a phenomenon called flapping), making words such as ladder and latter sound identical. For the Greek letters, flapping typically occurs for the bold t’s in beta, zeta, eta, theta, and iota.
| Letter |
Commonly used pronunciations |
 (alpha) |
ˈælfə listen |
 $ (beta) |
ˈbiːtə | ˈbeɪtə listen |
 (gamma) |
ˈɡæmə listen |
 (delta) |
ˈdeltə listen |
 (epsilon) |
ˈepsɪlɒn, ˈepsɪlən, epˈsaɪlɒn, ɪpˈsaɪlɒn | ˈepsɪlɑːn listen |
 (zeta) |
ˈziːtə listen |
 (eta) |
ˈiːtə | ˈeɪːtə listen |
 (theta) |
ˈθiːtə | ˈθiːtə, ˈθeɪːtə listen |
 (iota) |
aɪˈəʊtə | aɪˈoʊtə listen |
 (kappa) |
ˈkæpə listen |
 (lambda) |
ˈlæmdə listen |
 (mu) |
mjuː listen |
 (nu) |
njuː, nuː listen |
 (xi) |
saɪ, zaɪ, ksaɪ, ɡzaɪ listen |
 (omicron) |
əʊˈmaɪkrɒn | ˈɑːməkrɑːn listen |
 (pi) |
paɪ listen |
 (rho) |
rəʊ | roʊ listen |
 (sigma) |
ˈsɪɡmə listen |
 (tau) |
tɔː, taʊ listen |
 (upsilon) |
ʌpˈsaɪlən, ˈʊpsɪlɒn | ˈʊpsɪlɑːn listen |
 (phi) |
faɪ listen |
 (chi) |
kaɪ listen |
 (psi) |
psaɪ, saɪ listen |
 (omega) |
ˈəʊmɪɡə, əʊˈmɪ:ɡə, ˈəʊmeɡə, ˈəʊmeɪɡə | oʊˈmeɡə listen |
