Au vs. Aux

Question

Even though I do now understand the difference between when to use those two prepositions, I am having trouble pronouncing them.  Is there a way?  Is the X silent?  Thank you.

Accepted Answer

Rebecca, 
Au and aux are pronounced identically, except when there is liaison of 'aux' to the following word starting with a vowel or h muet (in this case the 'x' is transferred to the following word with a 'z' sound, as in this lesson example with "Je vais aux États-Unis') : 
 https://progress.lawlessfrench.com/revision/grammar/contractions-of-articles-a-le-au-a-les-aux-de-le-du-de-les-des
From the link below, you can also access further articles on when liaisons are required, forbidden or optional. This all takes time to acquire !.
 https://www.lawlessfrench.com/pronunciation/liaisons/