Hola Celia
At the moment all our content is based on Peninsular Spanish. We are working towards adding specific content related to Latin American Spanish, but still in progress.
As a general rule the main difference between vosotros and ustedes is that in Spain we use "vosotros" to refer to you plural in an informal way, so when we talk to friends, kids, and generally people that you know. There is a specific conjugation for the vosotros form in each tense. If we take for example verb hablar we'd say:
- Vosotros habláis muy bien español. (present tense)
- Vosotros hablasteis muy alto. (preterite tense)
etc
As you may know, in Latin America in general they won't use this pronoun. To refer to you plural they'd use "ustedes", and it will conjugate as the "ellos" form. For example:
- Ustedes hablan muy bien español.
- Ustedes hablaron muy alto.
If they are talking to people in a more formal context or to elderly people for example, both in Spain and Latin America the ustedes form will be used. (Here they coincide)
But you can read about this in our FAQs with a bit more detail:
Hope it helps
Inma