Usted versus Tu (and don’t forget the accent on the subject word, as without it means “your”) Understand that there are many variables in the subject words for “you” in Spanish. It’s handy to think of “tu” as the first name, informal version of you. Then think of usted as a shortened form of Your Grace, which is what you used in speaking to the king. Also, thinking of it this way makes it easy to remember that usted is third person singular. Think of…are you happy, good buddy? as opposed to…IS your grace happy today? In Latin America the ustedes form is used for the plural (think you all) form of both tu and usted. In Spain, however, the vosotros form is used for the plural you. Those are the basics, but you should know that there are many cultural and geographical nuances.
Some countries (Spain) move quickly to tu (using the verb “tutear” or the idiom “romper el turron” (a kind of nougat candy), while in Costa Rica even good friends and family are addressed as usted. It’s best to keep your ears wide open on this one and follow the local lead. But in general, use usted with strangers, in public situations (clerks, taxi drivers…women can be seen as flirtatious if they address a man in such a situation as tu), people for whom you wish to show respect (a good friend’s grandmother, an important position in a company), or to keep a professional distance. Use tu when speaking to a child, when speaking to family members, when praying (supreme beings are addressed as tu to show closeness), when you and the other person have agreed to use tu or when someone insists you address them as tu. However, it’s always better to err on the side of being too formal than too familiar.
Also pay close attention to learning all the irregular positive command forms for tu. Most of them are short, one syllable words – hacer: haz, decir: di, dar: da, poner: pon, salir: sal, tener: ten One possible theory for this is that it makes them very convenient to yell at your children when they are “sacandole las canas verdes”, literally pulling out your green gray hair, but figuratively, driving you crazy.