Register is the level of formality you choose when speaking or writing. In Spanish, register changes the choice of pronouns, verbs, and expressions. You use one register or another depending on your relationship with the other person and the situation.

Formal register is used with strangers, figures of authority, and in professional or institutional contexts. The goal is to show respect and maintain social distance. It is also common in formal letters, business emails, and customer service interactions.

Informal register is used with friends, family, and people you are close to. It allows a closer and more relaxed tone. It also appears in messages between peers and on social networks among acquaintances.

“Tú” is the informal pronoun and “usted” is the formal pronoun in most of the Spanish-speaking world. Switching between “tú” and “usted” also changes the verb conjugation. Choosing the right pronoun is key to sounding appropriate in each context.

In present, “tú” and “usted” take different forms in most verbs. For “tú” you use informal second-person singular forms. For “usted” you use the same forms as for “él/ella”.

Formal register typically uses courtesy expressions such as “please”, “excuse me” and “I appreciate it”. These expressions signal respect and soften requests or statements. In informal register you can be more direct and use fewer formulas.

In formal register diminutives and filler words are avoided and more neutral or elevated words are chosen. In informal register diminutives, contractions, and a more colloquial language are common. The formal tone is usually more careful and less direct.

The same situation is expressed differently depending on the register. The pronoun, the conjugation, and sometimes the degree of politeness change. Choosing the right version depends on whom you are addressing.

In regions where voseo is used, 'vos' is used as an informal form instead of 'tú'. The formal form remains 'usted'. Voseo changes the present tense conjugation and is common in everyday life in those places.

Choose “usted” and polite formulas in formal contexts and “tú” in informal contexts, adjusting the conjugation. Observe the environment and the relationship to decide the register, and change it if the situation requires. Recognizing these cues improves clarity and courtesy in communication.