ian in iang ing iong

ian = i + an; like English “yen”

“ian” reads as “ee-en” (quickly).  “an” after “ i” sounds between “man” and “men” in English.)

“in”(ien) sounds like “een” as in “seen,” like the “ine” in “machine.”

It is mostly spelt as “in.”

It sounds like “ee-ahng” without interference between the two.

“ing”(ieng) is similar to “ing” as in “ring.” 

iong = i+ong

It goes like “ee-ong” (quickly), almost like German “jung.”