Despoina K. answered 04/15/19
Passionate Greek tutor
Hey! This is not a question that can be answered in a sentence ... a general rule is that when the word is a female and ends in i then you use η but when it is neutral and ends in i you use ι , but this is just a general gramatic rule and has to do only with the ending of the word . inside the word or at the start it has to do with so many other grammatic,orthograpfic an historical rules. About how they sound it is absolutely the same :)