TH sound

[cryst38]

How do you teach the TH sound (student is saying a Z sound) and the W sound (student is saying a V sound)?

[5jj]

How do you teach (1) the TH sound (student is saying a Z sound) and (2) the W sound (student is saying a V sound)?

1. Model the /ð/ and /θ/ sounds, making sure that your student can see your tongue. If necessary, exaggerate the tongue position by poking it out too far and biting it (lightly!) Then gradually retract the tongue until it is in the correct position. Get the student to do the same.

2.Hold a straw in your open mouth. Form two vowels with a /w/ between them, for example: away, oh well, (h)e we(nt). Show that the lips and teeth do not touch the straw. Get the student to do the same.

[konungursvia]

What I do is first ensure they master /f/ and /v/, and then have them substitute the tongue in the place of the lower lip, and "try to make" the f and v sounds using the tongue. They turn out to be the target sounds you mention.

[DontBanMe]

How do you teach the TH sound (student is saying a Z sound) and the W sound (student is saying a V sound)?

Hey! Well, I must say I'm not a teacher But I hope this works for your students.
You know, I bet most of the teenagers love SUCKER. (stereotype I don't like it though). So, let's get it started. First, you ask your students to hold a lollipop just in front of their mouth and then ask them to try licking it. Thus, they will do the /th/ sound right. Here's the video link: http://www.youtube.com/watch?v=Ag4qoNzEH4w
As for the second question, I don't see why your students are having that kind of problem. ( They're obviously two different sounds). To make that sound, simply push your lips forward and blow out with a voiced sound. Link: http://www.rachelsenglish.com/consonant_w
Well, I hope you can demonstrate how those two sounds are made to your students. By the way, I'm so glad that your students have you as their teacher. Keep up the good work, dude!