Different Pronunciation

Hello, I'm new to Rocket French, so this may have been asked numerous, I don't know. My quetion is regarding different pronounciations I'm hearing in lesson 1.2. These are all basically the same issue, but I'm listing several examples. For instance the question "Comment vous appelez-vous?", Claire makes the S sound at the end of the first vous, but not the second. But while going through each word individually, she does not pronounce the S sound in the first vous. I believe the S should be silent, correct? In the statement, "Je viens des Etats-Unis." I think the the S in des is supposed to be silent, yet both Paul and Claire seem to be pronouncing it. Finally, in the Question, "Est ce que vous parlez français?", Paul seems to pronounce the ce in Est ce que, yet Claire does not. With all these examples, I'm just trying to figure out which is correct, or are they both correct? Is one proper and the other is the modified "street" French they mention in the lesson? Thank you and I'm really enjoying the course.

The s isn't silent in 'Je viens des Etats-Unis' because there's a vowel after des.

oh and with Comment vous appelez-vous, the same reasoning applies

Okay, thanks. I've got a lot to learn.

Yes, with respect to French euphony, ie. making the language "flow" as you speak it, whenever an "s" precedes a vowel or semi-vowel (ha-, ho-, etc.), a liaison is used and the "s" is pronounced like a "z", to make the sentence flow.

Nice question Jedediah and thanks to Claire and Pascal for answering it.It really helped me. I still find difficult to pronounce r,u like Claire does and i have been googling to find out the trick to do so.But since i have decided that my focus will be first to grasp the nitties-gritties and later to emphasize on pronunciation , i am having fun with Rocket French. I also have to practice my written french , don't want to write in this forum in english. Bonnee Journee

Bonjour! Merci beaucoup à Pascal et Claire for having explained the liaison perfectly! Don't forget every time a word ending in 's' precedes a word beginning with a vowel to pronounce the 's'. It makes the language far more fluid and easier to say. Je vous souhaite bonne chance pour vos études! Good luck with your studies! - Marie-Claire