My name is Kerstin and I am German so I know how it is pronounced. (Kare-Stin) is how it is pronounced. The "e" is a sharp "a" sound as in Care or Air, etc. My relatives from Germany have never called me "Chairstin" and if they did then they are messed up.
My sister is called Kerstin and in Germany it's pronounced Kare-steen. We live in England now and they spell it Kirsten here and they prounounce it kur-sten.
I lived in Germany for two years and the daughter of my landlady had this name. They pronounced it "kass-TEEN".
-- Anonymous User 12/22/2008
My middle name is Kerstin. It is pronounced Cher-stinn. My parents would have given it to me as a first name, but they do not like the alternate pronunciation KER-stin. Few people here in the U.S. seem to know about the Swedish pronunciation and it would be annoying to correct everyone all the time.