The formal question, written out
The standard formal greeting question is ¿Cómo está usted?, literally "How are you?" with the respectful pronoun. SpanishDict's guide glosses that string the same way and notes that usted itself is optional once the verb form already signals formality.
Evening formulas are in good night in Spanish.
RAE's Diccionario panhispánico de dudas entry on usted is the grammatical anchor. Usted refers to the interlocutor (second person of discourse) but is grammatically third person, so the verb must be third person: usted está, never usted estás. That is why formal "how are you" uses está.
Formal vs familiar forms in one table
| English intent | Spanish | Pronoun system | Verb form |
|---|---|---|---|
| How are you? (formal / respectful) | ¿Cómo está usted? or ¿Cómo está? | usted | está (3rd person) |
| How are you? (familiar) | ¿Cómo estás? | tú | estás (2nd person) |
| How are you? (plural, Spain familiar) | ¿Cómo estáis? | vosotros | estáis |
| How are you? (plural formal, or plural in much of the Americas) | ¿Cómo están ustedes? or ¿Cómo están? | ustedes | están (3rd person plural) |
RAE's basic grammar note on tú and usted describes usted as the cultured formal treatment in both Spain and Spanish America, with marked regional differences in how often people still choose it. In much of Latin America, ustedes is also the everyday plural for any group, formal or not, so plural "how are you" there is usually están, not estáis.
Do you need to say usted out loud?
Often no. ¿Cómo está? already points to usted (or to él/ella in a different context). In a greeting aimed at the person in front of you, listeners hear the formal register from está. Adding usted makes the respect explicit, useful with strangers, elders, clients, or anyone you would address as señor or señora.
SpanishDict's examples keep both patterns: Hola, señor. ¿Cómo está usted? and ¿Cómo está, señora? The shorter line is still formal. Switching to ¿Cómo estás? is what drops you into the familiar register.
Answers you are likely to hear
Common replies stay short: Bien, gracias. ¿Y usted? keeps the formal mirror. Muy bien or Todo bien work in either register; the follow-up pronoun (¿Y usted? vs ¿Y tú?) is what maintains or breaks formality.
This page covers the greeting question only. Regional greeting habits (qué tal, cómo le va, cómo está usted vs quieter openings) vary, and RAE's own notes stress that familiarity has expanded into situations that used to require usted. When unsure, está + usted is the safe default with strangers.