Whyn is chi pronounce as in archive and as in child?

Answer 1

I think that the hard pronunciation is for words derived from Greek (like archive) and the soft pronunciation for words derived from Anglo-Saxon (like child). I am sorry to be unable to help further.

Answer 2

Phonetically speaking, the word 'chi' is pronounced /kai/, that is, the phoneme /ch/ is pronounced as a /k/ as any good standard English dictionary would have a page informing on "Pronunciation and phonetic symbols in the dictionary". Therefore, one needs to verify how an unseen word is pronounced correctly. It's impossible to pronounce this word /chai/ since no one can understand what word you're saying.