Personal pronouns (I, you, he, she, it, we, they) in Spanish are easy, maybe except when you get to the 3 / 4 types of “you” that we have. Here’s a clear explanation:
English YOU vs. Spanish YOU
English You: English has only one word “you” to express You, singular (You, John, come please) and You, plural (All of you, come please).
Spanish You: Spanish has different words for «you» singular and «you» plural, but there is one added difference: it also has different words for «you» formal, and «you» informal, that is, «you» will be different words if you’re talking to your boss or if you’re talking to your friend. These 4 words are: tú, usted, vosotros/as, ustedes.
In Spanish from Spain
We said there are 4 words that mean YOU: tú, usted, vosotros/as and ustedes. How do you sort them out?
SINGULAR You: it means you’re talking to only one person, for example, you’re talking to a man named John, and you tell him «Can you send me the documents?»
Now, You SINGULAR can be either FORMAL or INFORMAL:
TÚ: informal. «¿Tú eres John?» (Are you John?)
USTED: formal. «¿Usted es John?» (Are you John, sir?)
PLURAL You (you guys, all of you): it means you’re talking to a group of people, for example, you’re talking to your co-workers, and you tell them «Can you send me the documents?»
Now, You PLURAL can be either FORMAL or INFORMAL:
VOSOTROS: informal. «¿Vosotros sois John, Mary y Alan?» (Are you John, Mary and Alan?)
USTEDES: formal. «¿Ustedes son John, Mary y Alan?» (Are you John, Mary and Alan? This might be a work situation, for example)
Notice that the FORMAL versions, USTED and USTEDES look very similar, only USTED is singular and USTEDES is plural. The INFORMAL versions will be TÚ and VOSOTROS.
In LATAM (Latin America)
In LATAM, the only difference is that VOSOTROS doesn’t exist. So, if you want to use YOU PLURAL, the only option is USTEDES. So, it’s neither formal nor informal, that will depend on context. As for YOU SINGULAR, tú is still informal, and usted is still formal.