According to this article:
The Pronunciation of ‘C’ and ‘G’ generally (but not always) depends
upon the letter following either 'C' or 'G'. If the following letter
is ‘E’, ‘I’ or ‘Y’, the pronunciation is said to be “soft” (as in
cell & large). If the following letter is anything else – including a space – the pronunciation is termed “hard”. (as in call & great)
I'm wondering if these letters (‘C’ and ‘G’) retain their pronunciation in blend words.
For example consider the word "Regex". This word is made from combining "Regular" and "Expression". How should the letter "g" in Regex be pronounced? Soft, like in "General"? or hard, like in "Regular"?
Best Answer
There is no "should" or prescriptive rule for pronunciation of unfamiliar words. What people do which resembles a rule is to apply common patterns, such as soft g before e, when a new word comes along.
As this new word circulates, you are likely to hear a lot of “rEH-jeks”, following the common pattern, but also a lot of “rEGG-ex”, after the word “rEGG-u-lar”. And eventually one will win the day. We'll just have to wait to see how it turns out.