Ancient Greek

Warning: this is both long and simplified, which is a terrible combination.

There are three ways to pronounce Ancient Greek names:
--reconstructed Ancient Greek (what most scholars believe the language actually sounded like)
--Latinized (how the Romans pronounced the names when they imported them)
--Anglicized (how we usually say them today, which is based off the Latinized versions)

The letters are mostly the same as English, but there are some exceptions:

• A (Α, α) -- "ah" (like 'father') in Ancient Greek and Latin. In English, like "a" ('cat') or "ah" ('father') or "ay" ('play').
• C (Κ, κ) -- always hard ('cat') in Ancient Greek and Latin. In English, like our C: hard before a, o, u ('cat'); soft before i, e, y ('cent'). Also soft before 'ae'.
  Latin didn't have the letter K, so older transliterations will have C. More authentic transliterations will use K (which English adopted directly from Greek).
• G (Γ, γ) -- always hard ('gift') in Ancient Greek and Latin. In English, like our G: hard before a, o, u ('go'); soft before e, i, y ('gem'). Also soft before 'ae'.
• I (Ι, ι) -- "ee" in Ancient Greek and Latin; in English, "ih" ('it'), "ee" ('see'), or "eye" ('sight'). Usually 'ih' if followed by two consonants, otherwise whichever is easiest to say, it seems. 
• X (Ξ, ξ) -- "ks" in Ancient Greek and Latin; in English "z" at the start of a word ('xylophone'), "ks" otherwise.
• Y (Υ, υ) -- "eu" in Ancient Greek (doesn't exist in English; think of the French 'u'); "ee" in Latin. In English, like I, basically a toss-up. 
• U (Υ, υ) -- "eu" in Ancient Greek (doesn't exist in English; think of the French 'u'); "oo" in Latin; "oo" in English, or "yoo" when at the beginning of a word.
  (yes, the letter upsilon (Υ, υ) is written either Y or U. If after another vowel, it tends to be written as U, and as Y after consonants)
• CH (Χ, χ) -- "kh" in Ancient Greek and Latin; "k" in English.
• PS (Ψ, ψ) -- "ps" in Ancient Greek; "s" in Latin and English.
• TH (Θ, θ) -- "t'h" in Ancient Greek and Latin (an aspirated T, rather like a 't'-sound followed immediately by a 'h'-sound); "th" in English ("thigh").
  (Interestingly, in Modern Greek, TH is now pronounced "th".)

I've saved the two trickiest for last--E & O. Both are represented by two letters in Ancient Greek, and the pronunciation depends on which.

• E can be either from epsilon (Ε, ε), which is short ('let'), or eta (Η, η), which is similar to the long English "ay" sound ('play'). When Anglicized, the eta says "ee" ('see'), and sometimes the epsilon does too.
• Similarly, O can be either from omicron (Ο, ο), which is short ('cot') or omega (Ω, ω), which is long ('coat'). When Anglicized, both tend to follow English pronunciation rules.
  Names ending in -os are usually changed to -us in Latin and English.

Ancient Greek uses the following digraphs:

• ai (αι) -- "eye". Written as ae in Latin, still pronounced "eye". Often ae in English as well, but then is pronounced "ee" or "eh".
• au (αυ) -- "ow", like 'cow'.
• ei (ει) -- "ay" in Ancient Greek and Latin, usually "eh" ('set') or "ee" ('see') in English.
  Often written as just e or i in Latin and English (e.g. Rheia --> Rhea; Dareios --> Darius).
• eu (ευ or ηυ) -- "eh-oo" in Ancient Greek and Latin, "yoo" in English ('Europe').
• oi (οι) -- "oy", like 'boy'. Written as oe in Latin, and usually in English as well, but then pronounced "ee" (not to be confused with the name ending -oe, which is two separate vowels, οη or ωη).
• ou (ου) -- "oo", like "boot". Often written as just u in Latin and English (and in English, then pronounced "yoo" at the start of the word, like in 'Uranus').
• yi or ui (υι) -- "oo-ee" in Ancient Greek and Latin, "ee" in English.

So, that was easy, right? :p On to stress!


--Ancient Greek
Ancient Greek used tonal stress, which is something that a native English speaker will have a hard time imagining, let alone pulling off! Most just approximate it by using the dynamic ("loudness") stress we Anglophones are used to.
(aside: stress is something that's generally quite lacking in pronunciation guides, and if you want a really in-depth look, I suggest this page: http://enargea.org/homyth/translit.html, which is amazingly thorough on stress differences in Ancient Greek and Latinized pronunciations)
If you happen to have the actual Greek spelling of the name, you can often quite easily tell where the stress is--many names have the stressed syllable marked with the acute accent (ά, έ, ή, etc).
If the name does not have the accents marked, it can get quite complicated since stress is dependent on word length and vowel length (really, the simplest way might be to just stick the Greek spelling into Forvo)!

• Two-syllable names are usually stressed on the first. 
• Greek often has final-syllable stress, particularly in names ending in -o, -is, -os or -us. 
• If the name ends in -as, -on, -e, -ia, or -ea, it's usually the second-last syllable stressed (but not -eia, however! Those are stressed on the third-last).
  Remember that the vowel pairs -oe, -ia and -ea are separate syllables, so the stress would be on the o, i, or e (Beroe = "beh-RAH-ay"; Delia = "day-LEE-ah"; Leucothea = "lyoo-koth-EH-ah").
• With longer names, the third-last is usually a good guess, especially if the name does not fall into one of the previously mentioned patterns. 

We're used to Latinized pronunciations, so if it sounds awkward, you're probably pretty close. :p


--Latin and English

• If you don't care about attempting Ancient Greek accent, and are content with Latinized or Anglicized, just stress the second-last syllable.
• Common exceptions are when the name ends in -ia or -e (Eumelia = "yoo-MEL-ee-ah; Antigone = "an-TIG-on-ee"), or -ias, -ion, or -eus (Callias = "KAL-ee-us", Endymion = "en-DIM-ee-on", Proteus = "PRO-tee-us").
• With names of 4 syllables. it's sometimes the third-to-last that's stressed (Eidothea = "ed-OTH-ee-ah"), but not always (Amalthea = "am-al-THEE-ah").

Here are a few names, showing common differences in the three pronunciation methods.

	Ancient Greek	Latin	English
Psyche (Ψυχή)	"psoo-KHAY"	"SEE-khay"	"SYE-kee"
Theseus (Θησεύς)	"t'hay-seh-OOS"	"T'HAY-seh-oos"	"THEE-see-us"
Kelaino / Celaeno (Κελαινώ)	"kel-eye-NOH"	"kel-EYE-noh"	"sel-EE-noh"
Chryseis (Χρυσηἰς)	"khroo-say-EES"	"kree-SAY-ees"	"krye-SEE-is" or "kris-AY-is"
Medousa / Medusa (Μέδουσα)	"MED-oo-sah"	"med-OO-sah"	"med-OO-sah"
Diogenes (Διογένης)	"dee-ah-GEN-ays"	"dee-AH-gen-ays"	"dye-AH-jen-eez"
Adrasteia (Ἀδράστεια )	"ah-DRAHS-tay-ah"	"ah-drahs-TAY-ah"	"ad-ras-TEE-ah"