I know as a foriegner sometimes I mistake x sound for sh or sh for x when people speak very fast or not very clearly, like sometimes I mistake 想 and 上 etc but they are a different sound to each other. for sh sound I was taught to roll the tounge back in the mouth, there also seems to be less air coming out of the mouth when you say sh. For x your tounge is behind the lower front teeth and its a more aspirated sound.

X's pronounciation likes the letter "E", but not like "sh" You can put your tongue to the place of the letter E, don't move your tongue,then try to prounounce "x"

You have to understand that the Latin letters Pinyin are not English. Mandarin is very poor in sounds, still, there is an initials oversupply of SH, ZH, S, Q, J, X, CH etc. which are sort of similar. X is like SH, but with less air, or a strong S. Don't worry if you get it a bit wrong, but don't confuse it with the X that is used in English, that would be too wrong.

it doesnt sound like "sh".it's hard to explain how it sounds like here,let me try,x is produced by drawing the front of the tongue toward the hard palate,and squeezing the air out between them. it's a little bit confusing,if you still dont understand,tell me your email,i can record it and send to you

sh is not x....all english natives have this problem and some other nations as well, but remember - chinese is not about pinyin, it is about character!!!....pinyin is for foreigners, chinese dont care....who pronounce x as sh, it's not correct!!!!