For instance, "vous" has a silent "s", unless it's something like "Je vous ai vu." (I'm not sure that I constructed that properly, but you get the point-- the "s" is pronounced in that case.)
But what if you have "Je voudrais acheter un billet." ? Is it "voo-drez"?
Basically, I'm asking do you always pronounce it if the next word begins with a vowel, or only under certain circumstances?