BEGINNIG AN ORAL OR WRITTEN COMMUNICATION

1. Beginning a conversation

We can use some simple phrases like..
Hola = Hi/Hello

¡Buenos días! = Good morning

¡Buenas tardes! = Good aftern
oon

¡Buenas noches! = Good evening 

*As a logical thought, when we say 'Buenos días/tardes/noches' we refer  just to one day 'Buen día' 'Buena tarde' and 'Buena noche', doing a literal translation from the english, is exactly how it should sound. But, the Royal Academy Spanish has said that the properly way is in plural, doesn't matter if we are not talking of many days.

How are you? = ¿Cómo (le) te va?

How's it going? = ¿Qué tal?

What's news? = ¿Qué hay de nuevo?

2. Beginning a letter

Informal: Directed a person who we treat as a familiar form.

We can use "Querido" (masculine) and "Querida" (feminine) = "Dear" before the words like "mamá" = "mom", "papá" = "dad" or "amigo" = "friend".

Formal: We use this for business, request of employment, request of information.

  

Estimado señores = "Dear Sir(s)"

Estimada señora = "Dear Madam"

Estimado Señor Pérez = "Dear Mr. Pérez"

Estimada Señora Pérez = "Dear Mrs. Pérez"

A quien corresponda = To whom it May Concern 

Summary:

 In english we use only "Dear" but in spanish, we use "Querido" when we refer  to friends and family and "Estimado"when we refer  to other people who we don't know very well or we respect.

* Please if you have any question just let me know (:
and follow me @GermieCragua !