Tú vs. Usted
I know your first instinct is going to be to tell me that this question is asked and answered, but I looked and I didn´t find it. I know the difference between tú and usted to the level of the reference section. I think my question goes a little deeper than that. I recently moved from the United States to Santiago Chile for work and there are a variety of situations in which people have used the tú form with me (superiors, female peers, older co-workers).
My question is: if a native Spanish speaker uses the tú form with me, can I assume that I should follow suit? Or are there some situations in which one person in a relationship uses tú and the other person uses usted, like the way in English a subordinate might always call his boss "sir"? I'd be interested to hear from people with experience or knowledge from any country, especially Chile. Perhaps this varies from country to country. Thanks.
3 Answers
I believe you would use the same common sense you use when addressing people in English. If someone is close to your age or younger, assume that the informal approach is appropriate. However, it is always wise to continue addressing someone significantly older or in a place of authority in a more formal way. I'm sure they will tell if you if you can use the tú form or not.
Also, if you are a person who is not afraid to just come out and ask (like me 
)...go for it.
In my experience in some places, like the Dominican Republic, the informal is used exclusively. That makes things quite simple. But I'm guessing this is the exception and not the rule.
First read what Nicole-Baile said.
When I speak to my teachers I use the "usted" form. But when they speak to me they use the "tú" form. Sometimes people will tell you "puedes tutearme" or something like that. It means you can treat them using the "tú" form.
In Venezuela the tú form is used almost exclusively by everyone. Your best bet is to listen to the people around you and see how the native speakers from that area use it.
