Formal / Informal speech in Spanish

Question

How do you recognise a formal or informal way of speaking spanish?

Are there any rules?

Answer 1

Addressing a person in a formal manner requires use of the third-person conjugation.

For example, when you would say sir/ma'am or when speaking to someone you do not know.

Answer 2

Use tú with the tú conjugation for informal speech. In Central America, use vos instead of tú and use the vos pronounciation for the verb. For example:

tú comes o vos comés

As danrivera said above, in formal speech you would use the Ud. conjugation.

¿Habla español? ¿Come tacos?

But I don't think this is the question you are asking, I think you are asking if you can recognize formal speech or informal speech just by listening to people talk. And my answer is yes, same as in English. Formal speech is using correct grammar and correct pronunciation of words whereas informal speech is using colloquialisms, dialects and not necessarily correct grammar. It's the same as if you heard young people speaking English to their friends and professors or scientists or erudite persons speaking English to their colleagues. Just as you can tell that a journalist's speech on the evening news is formal whereas a teenager's speech with his friends is informal.

Thanks very much for your help. - Flanno, May 25, 2011