Phi (Φ φ) has an f sound, similar to the f in the English word "fat.".
Ksi (Ξ ξ) has a ks sound, similar to the x in the English word "fox." This letter is always pronounced the same, regardless of where it appears in a word.
Theta (Θ θ) has a th sound, similar to the th in the English word "think." Delta (Δ δ) also has a th sound, but it is softer, similar to the th in the English word "this.".
However, this Greek letter actually has a v sound, as in the English word "vet."
You may be tempted to pronounce beta (Β β) the way you would an English b.
They are all pronounced like the ee in the English word "meet."
Eta (Η η), iota (Ι ι), and upsilon (Υ υ) are the 3 i letters in the Greek alphabet.
Memorizing them will make it easier for you to pronounce Greek words, even if you're reading the word transliterated into the Latin alphabet. While the Greek alphabet shares many commonalities with the Latin alphabet, there are letters that may have a different pronunciation than what you would expect. Memorize Greek letters with distinct pronunciations. It sounds like the s in the English word "soap." Note that the lower-case letter has a different form if it occurs at the end of a word.
Sigma (Σ σ/ς) does not look like the Latin s, but is pronounced the same.
It sounds like the p in the English word "pot."
Pi (Π π) does not look like the Latin p, but is pronounced the same.
It sounds like the l in the English word "lap."
Lambda (Λ λ) does not look like the Latin l, but is pronounced the same.
The Greek letters zeta (Ζ ζ), kappa (Κ κ), mu (Μ μ), nu (Ν ν), and tau (Τ τ) look like the Latin letters z, k, m, n, and t, and share the same sounds.
Both omicron (Ο ο) and omega (Ω ω) have an o sound, similar to the o in the English word "got.".
Alpha sounds like the a in the English word "father." Epsilon sounds like the e in the English word "pet."
The vowels a (alpha, Α α) and e (epsilon, Ε ε) are equivalent to the short version of these vowels in English.
If you get these under your belt, you'll already be able to pronounce nearly half of the Greek alphabet. There are about 10 letters in the Greek alphabet that have the same sounds as their counterparts in the Latin alphabet. Recognize Greek letters that share pronunciations with Latin letters.