How to pronounce these Greek letters?

[QueenZ]

1. μνηστευθείσης - how to pronounce "μν" in this word? Is it "m" or "n" or "v" or "mn"??

2. πνεύματός - how to pronounce "πν"?

[spiphany]

They are pronounced like "mn" and "pn", as far as I know. English doesn't allow these combinations of consonants at the beginning of a syllable, but Greek does, as do some other languages (for example, Russian has similar combinations of sounds). These sounds do occur in other places, however: consider "am not" or "dampness". (It may help at first to stick a very brief vowel sound between the two consonants while practicing, since this is a sound that can be difficult to produce.)

[calvinist]

Yes, spiphany is right, they are pronounced "mn" and "pn". The reason it seems strange to us is a linguistic phenomenon called phonotactic constraints. Every language has a limited number of consonant clusters it allows and they very depending upon the position in the word. So, just because "mn" isn't allowed in English means nothing as far as Greek is concerned. Consider Japanese, which doesn't allow consonant clusters at all, except with /y/ which is a semi-vowel as in "Tokyo". The Japanese borrowed the word "baseball" as "beisubooru", inserting a vowel between /s/ and /b/ in order to comply with the phonotactic constraints of their language. "mn", "pn", and "ps" as in "psalm" may be hard for us native English speakers to pronounce, but with a little practice it won't feel so strange.