It depends... For example, here in Argentina we don't use "vosotros" (and even more, Spain is the only country that really uses it as pronoun), we use insted of that "ustedes". Other difference between Argentina and Spain spanish, it's that we don't say "tú" (it also happens in Uruguay and other countries), we say "vos". The letter "Y" in Argentina and Uruguay, and the letter "Ll", should be pronounced like a "J" or "Sh". That's the biggest difference about pronunciation. And also, you have to see the vocabulary. There are some differences between the different languages. The

It actually depends on the country, in South America there's quite a wide range of diversity, not only the accent but also in common vocabulary. We in Spain have a good laugh on some South American soap operas with their funny words and I assume they will find our Spanish weird as well- Within Spain there's also quite a great difference in pronunciation between Northen and Southern Spanish, but you see here the differences in vocabulary here are less obvious

According to my teacher, American Spanish doesn't use 'Vosotros'. Otherwise, some of the letters are pronounced differently (j, v..)