I think you need to give a little more information in this question. If you are asking what each of these letter combinations sound like then you are better off speaking to someone I'm person as it is hard to communicate. As a guide 's' is a sound created by letting out air though a small gap. It sounds similar to a snakes hissing sound Eg. Silly snakes snack on steak. 'Sh' is a soft soothing sound. It is formed also through blowing out air bit through a bigger gap. It is the sound people make when telling someone to be quiet. Eg. Should shells shine? 'Th' is a sound created by placing your tongue on your top teeth and letting out air. It is a harsher sound than 's' or 'sh' Eg. Then this thoughtless fool thanked me. Hope this helped