Counting in Spanish begins with Cero (0), Uno (1), Dos (2), Tres (3), Cuatro (4), Cinco (5), Seis (6), Siete (7), Ocho (8), Nueve (9), and Diez (10). Uno is special because it shortens to un before masculine nouns, as in un libro ("a book"), and to una before feminine nouns, as in una mesa ("a table"). Larger round numbers follow a similar pattern: Veinte (20), Treinta (30), Cincuenta (50), Cien (100), and Mil (1000). One important twist is that Cien becomes Ciento when it appears before another number, so 101 is ciento uno rather than cien y uno.
Time of day is described with a set of familiar expressions. To ask the current time, use ¿Qué hora es? and respond with ser: Es la una for one o'clock and Son las dos (or tres, cuatro, and so on) for any later hour. Day-to-day references rely on Hoy (today), Mañana (tomorrow, which also means "morning" when used with the article), and Ayer (yesterday), which typically pairs with the preterite tense. The words La mañana and La tarde refer to the morning and afternoon periods, often used in the phrases por la mañana ("in the morning") and por la tarde ("in the afternoon").