I heard the sentence “je suis desolé” read by a native audio program flashcard app as just “je–suis–désolé”, but then I listened to another one with “suis” in it: “je suis américain” and am I dreaming or is there a slur like “je–swiss–américain” as if the suis is slurred? I tried to find another way to confirm online but I couldn't. On my Ivona Text-to-Speech app there is no slur in the sentence “je suis américain”. Which one is accurate?
As you may know, in French some letters are silent when they are at the end of a word, for example "s", "t", "d" and "p" (this is what I was taught when I was young).
So, the word depot is pronounced as if the final t were not there, and the same happens with suis, il entend et coup, just to give you a few examples.
However, because of the thing called liaison, when a word ending in "s" is followed by another word starting with a vowel, the consonant is slightly pronounced and for this reason you say "Je sui- zAméricain" as much as you say "Je sui- zItalien", or "Je sui- zEspagnol".
I forgot to add another frequent expression where you need to create such a liaison, that is pas encore.