In spanish the letter "c" can be pronounced in 3 ways depending of each word. It could sound like the english "s" , "k" or "th". It sounds like "s" if it is in front of the vowels "e" or "i", for example "Cesar", "Cigueña", "perece", "percibe". In Spain, this is the case of the "c" that sounds almost like "th", in order to distinguish it from the letter "s". In front of the vowels "a", "o" or "u" it sounds like the english "k" of kentucky or "kilogram. It hapends the same in Spain. For example: "casa", "panoramica", "comer", "Mexico", "cubierto", "cuneta", etc. In front of a consonant letter it always sounds like "k", for example: "fractura", "micción", "fracción", etc.

In standard Spanish of Spain that sounds "C" hard, as in "cien". In some countries (mainly in Center or South America), you can hear that pronounced as "S". Best regards, Cristina