Is hola formal or informal
Hola is a widely used Spanish greeting meaning hello. It works in many ordinary situations and is not restricted to close friends. Whether it is sufficient in a formal setting depends on the context and any words that accompany it.
Meaning and context
A greeting is only one part of how formality is expressed. Titles, forms of address, the relationship, and the purpose of the conversation also matter. A more formal opening may use buenos días or buenas tardes, followed by an appropriate title or name.
Examples and usage
Hola, Marta is a straightforward greeting to someone named Marta. Buenos días can open a more formal daytime interaction. In correspondence, a business may expect its own conventional opening rather than the same greeting used in a chat message.

What to check
Do not confuse familiarity with disrespect. A common hello can be polite when the rest of the exchange is respectful. For an unfamiliar official or a formal written request, follow the organization’s conventions and choose a clear, courteous introduction.
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