My name is Megan Brach. I've been teaching english as a second language for four years. Learning english isn't fast, nor is it easy. But I'm going to help you get started. Are you ready? Lets learn english. Now lets practice the difference between the s' and the z' sounds. First, you're going to put your tongue behind your bottom teeth and aspirate. For s' you do not use your vocal cords. So try it. Glass, sister, sweets, swing. Now, lets try z', again same mouth shape, but now you use your vocal cords. Buzz, zipper, jazz, zoo. Do you feel the difference? Practice. And that's the difference between the s' and the z' sound.