The formal would be "¿Dónde vive?" or, if you want to avoid confusion with "he" or "she", "¿Dónde vive usted?"
The correct conversion of 'Dónde vives' to formal Spanish is '¿Dónde vive usted?'
In Spanish, "you are not" is translated as "no eres" (informal) or "no es" (formal).
Both "has striven" and "has strived" are correct. "Has striven" is more commonly used in formal writing, while "has strived" is acceptable in both formal and informal contexts.
"¿Cuáles son formales y cuáles son informales?" is a question in Spanish meaning "Which ones are formal and which ones are informal?" It is used to inquire about the level of formality of something, such as names, greetings, or requests.
Informal
The 12 personal pronouns in Spanish are: yo (I) tú (you, informal singular) usted (you, formal singular) él (he) ella (she) nosotros (we, masculine) nosotras (we, feminine) vosotros (you all, informal plural masculine) vosotras (you all, informal plural feminine) ustedes (you all, formal plural) ellos (they, masculine) ellas (they, feminine)
como esta (formal) como estas (informal) como esta (formal) como estas (informal)
como esta (formal) como estas (informal) como esta (formal) como estas (informal)
Tu-informal/singular Vous- formal/plural
tú (informal, singular)) usted (formal, singular) vosotros (informal, plural) ustedes (formal, plural)
Tú (informal) or usted (formal)
¿De dónde es usted? (formal) ¿De dónde eres? (informal) ¿Ustedes de dónde son? (formal and informal plural in Spanish America, only formal in Spain) ¿De dónde sois? (informal plural but only in Spain) To ask someone where they are from in Spanish, you can use the formal or the informal: Informal: ¿De dónde eres? Formal: ¿De dónde es usted?
Ya has/ha/habeis/han comido? (Singular-informal/-formal/plural-informal/-formal)
It depends how many people you are addressing and if you wish to make it formal or informal No limpia (informal single) No limpie (formal single) No limpiéis (informal plural) No limpien (formal plural)
Puede usted/puedes contestar (formal/informal)
tu/su bandera (informal/formal)
Que te/le//os/les gusta hacer (singular informal/formal//plural informal/formal 'you')
Tu (informal singular) Usted (formal singular) Vosotros/as (informal plural, male/female) Ustedes (formal, plural)