Para de decir "tú" cuando se requiere "usted" (Stop saying "tú" when you need to say "usted")

 ¡La gramática de nuevo! ¡Que aburrida! 😩Seguro que estaréis pensando en esto ahora. Pero como no podemos ignorar la base de un edificio, de igual modo, no podemos ignorar la gramática porque os guste o no os guste, la gramática es la base de todos los idiomas y la debemos aprender. Pero ¡no os preocupéis! lo vamos superar.👌👍

 Despite the fact that Spanish is a pro-drop language (pronoun drop language), one must be acquainted with the use and rules of the Spanish personal pronouns, i.e as to how and when to apply each especially when it comes to learning the use of the second person pronoun, because unlike the English language where "You" is used in all situations (whether singular or plural or formal or informal), the second person in the Spanish personal pronoun (el pronombre personal) is a little bit more complicated to apply in sentences than it appears.

How and when to use (Como y Cuando se aplica)

  Here, the occasion is taken into consideration likewise the number.

The occasion: This simply refers to formal and informal situations.
 - In a formal situation, one tends to address one's superior, like the boss (jefe/ jefa), teacher (maestro/ maestra), lecturer (profesor/ profesora), one's elder (ancianos), an unfamiliar figure (that is to say un desconocido /una desconocida (a stranger)); someone you're just meeting for the very first time. Therefore in other to show respect one is expected to apply el "usted" form, which always goes with conjugation of the third person pronoun.

Por ejemplo (For example):
Esta es una conversación entre María y su jefa (This is a conversation between María and her boss)
-María: Buenos días señora García. ¿Cómo está (usted)? Good morning Mrs. García. How are you?
-Jefa: Buenos días María. Muy bien. ¿Y usted? Good morning María. Very well. And you?
-María: Bien, gracias. Si (usted) tiene un momento, me gustaría entregarle (a usted), el resumen de la última reunión. Good, thanks. If you have a moment, I would like to submit the summary of the last or previous meeting.
-Jefa: Por supuesto María. ¡Pase! Of course Maria. Go ahead!

Una conversación entre dos desconocidos (Conversation between two strangers)
-A: Buenos días. ¿Cómo se llama (usted)? Good morning. What is your name?
-B: Buenos días. Me llamo señor B. ¿Y usted? Good morning. My name is senor B. And you?
-A: Me llamo señora A. Encantada de conocerlo u encantada de conocerle (a usted). I am senora A. Very pleased to meet you.
-B: Encantado. Likewise.

In an informal situation, the ball is in your court to behave freely and relaxed because one tends to be found among peers, friends, family or in hierarchy, one's inferior.
Here, the use of "tú" is advisable, which follows the conjugation of the second person pronoun.

Por ejemplo:
Una Conversación entre amigos (Conversation between friends)
-A: ¡Hola! ¿Cómo estás (tú)? Hello! How are you?
-B: Bien. ¿Y tú? Good. And you?
-A: Bien. ¿(Tú) Tienes tiempo para acompañarme a hacer la compra esta tarde? Good. Do you have time to accompany me shopping this afternoon?
-B: Sí, claro. Yes, of course.

Una conversación entre un profesor y su alumno (Conversation between a lecturer and his student)
-Profe: ¿Cómo te llamas (tú), chico? What is your name boy?
-Al: Me llamo Fernando. My name is Fernando.
-Profe: ¿De dónde eres (tú)? Where are you from?
-Al: Soy de Nicaragua. I am from Nicaragua.

The number:
   This simply means the singular or plural. Therefore according to the grammatical rules, el "tú" becomes vosotros/ vosotras in the plural form, (that is when you're addressing more than one person in an informal situation) (solo en España), whereas el "usted" changes to "ustedes" in the plural form (that is when you are addressing more than one person in a formal situation.) (Solo en España). So, as the pronouns change, so will their conjugations; vosotros/ vosotras is now conjugated in the second person plural, while "ustedes" is conjugated in the third person plural.

Por ejemplo:
Vosotros/ Vosotras
Una Conversación entre un profesor y sus alumnos (Conversation between a lecturer and his students.)

-Profe: Chicos, ¿Cómo estáis (vosotros)? ¿(Vosotros) Ya habéis hecho los deberes? Boys and girls, how are you? Have you done your homework already?
-Als: Sí, profesor. Yes

Ustedes
Conversación entre tres desconocidos (Conversation between three strangers)

-Des 1: Buenos días, ¿Cómo están (ustedes)? Good morning, how are you?
-Des 2 & 3: Muy bien. ¿Y usted? Very good. And you?
Des 1: Bien. ¿De dónde son (ustedes)? Good. Where are you from?
Des 2 & 3: Somos de México. We are from Mexico.

El voseo "vos"
In place of "tú", in some Latin American countries like Argentina, Bolivia, Costa Rica, México, Nicaragua, Paraguay, El Salvador, Uruguay and Venezuela, the use of "vos" is predominant and can be considered to be more popular than el "tú". So in informal situations in most of these countries mentioned, the use of "vos" is very common.
However the conjugation of "vos" which differs in each country according to RAE, neither follows the second person pronoun rule nor the third person, it has its own form which is por ejemplo: "Vos tenés dinero"(You have money), "Vos sos de Bolivia " (You are from Bolivia).

Fíjate:

-El "vosotros / vosotras is only used in Spain.
-While in Latin America, El "ustedes" is used both in informal and formal situations alike.
-El uso de "tú" es "tutear" ( The use of "tú" is "tutear" (the verb) and el "tuteo" (the noun))
-El "usted" y "ustedes" can be abbreviated as follows: usted (Vd. or Ud.), ustedes (Vds. or Uds.)