What's the difference between an island and and isle? My translator translates those two words into the same word, so I can't figure it out.

And a quick question about the American anthem (I'm not sure if this is the right forum to ask the question, but I'll ask anyway) - I've looked for the words of the American anthem, and I found this:
http://www.usconsulate.org.hk/pas/kids/anthem2.htmIt seemed really long, so I went to Youtube to hear it. Apperently whenever I heard it, only the first stanza (I hope I used the right word

) was being sang (Is it sang or sung?). Is it always like that? When Americans sing the American anthem, do they sing only the first stanza? Not all of it?
Thank you for your answers!

Barack, Israel.