[jack2312]

Huh, having learned Spanish as a non-native speaker, I was taught that the two forms had more to do with the closeness of the relationship than they did with some sort of social rank or superiority.

For example, a family member who you would address as "sir" (at least in the Southern U.S.), maybe a parent or grandparent, might be taken aback if you addressed them with the formal "usted" in Spanish, because it didn't imply respect, but that you didn't consider the person close. Another example would be prayer, where God is definitely superior to us, but you would address Him with the less formal "tu", because the love He has for us makes that a close and personal relationship. (I'm not even sure that the word "formal" is the right one to use here, as like I say, it's not quite the same as in English.)

You could also have a business conversation where you'd use "usted" without necessarily implying respect, because "tu" sounds out of place for a distant relationship like that. (I.e. using "tu" wouldn't be disrespectful, so much as it would just be weird or akward.)

Am I misunderstanding the usage of the two forms, or could someone enlighten me a bit more on the subject? Is the dynamic similar in other T-V languages, or is it used more to denote social status/tiers?

[moffkalast]

Not sure about Spanish, but in Slavic/Germanic languages it's as OP says, the plural form tends to show more respect for e.g. talking to a stranger, especially an older one. Students typically address teachers this way and teachers don't do it in return, until university where students are considered old enough and it's typically done mutually. People of the same age that know each other almost always just use singular form.

There are actually three forms if we're completely exact: singular 2nd person, plural 2nd person, and plural 3rd person. German uses the first and last, Slavic languages have all three but the third is very dated and practically unused by now.

[mijamo]

It is not that easy and depends a lot on context. I know people who use "usted" to their grandparents (who use "tu" in returns), but at the same time you have lots of shops where they will say "tu" to their customers (particularly clothing, not so much for restaurants). Depends a lot of the country/region and even family.

[jack2312]

Thank you to those who responded! If you happen to see this, do you know if the behavior you describe is more common in Europe, rather than the Americas? (Just out of curiosity.) Most of the people I know who speak Spanish are from Mexico, Central America, and the Caribbean (Puerto Rico or Cuba), and occasionally from South America. Rarely do I get to meet people from other areas, so I'm not sure if this is something I've failed to notice, or if it's maybe due to a regional difference.

Also, am I correct in my understanding that prayer is done nearly universally in "tu"? (I know some Argentinos who use "vos" for informal circumstances, but still use "tu" for prayer, but rarely anywhere else.) Could you help me to better understand the reasons behind this?

Thank you again for your response! It's a beautiful thing to have the opportunity to learn about other cultures from the people who live them.