"One, two, three, four, five" in Spanish?	Uno, dos, tres, cuatro, cinco. Uno shortens to un before a masculine noun: un libro.
"Six, seven, eight, nine, ten" in Spanish?	Seis, siete, ocho, nueve, diez.
"Eleven to fifteen" in Spanish?	Once, doce, trece, catorce, quince.
"Sixteen to nineteen" in Spanish?	Dieciséis, diecisiete, dieciocho, diecinueve. Each is written as one word.
"Twenty" and "twenty-two" in Spanish?	Veinte. Veintidós. Numbers 21 to 29 are single words: veintiuno, veintitrés, veintiséis.
"Thirty-one" in Spanish?	Treinta y uno. From 31 upwards, tens and units are separate words joined by y: cuarenta y cinco (45).
"Forty, fifty, sixty" in Spanish?	Cuarenta, cincuenta, sesenta.
"Seventy, eighty, ninety" in Spanish?	Setenta, ochenta, noventa.
"One hundred" vs "one hundred and five" in Spanish?	Cien for exactly 100 (cien euros). Ciento for 101 to 199: ciento cinco (105).
"Five hundred" and "one thousand" in Spanish?	Quinientos (irregular, 500). Mil (1,000), with no un in front: mil personas.
"Monday, Tuesday, Wednesday" in Spanish?	El lunes, el martes, el miércoles. Days are masculine and written in lower case.
"Thursday, Friday, Saturday, Sunday" in Spanish?	El jueves, el viernes, el sábado, el domingo.
"On Mondays" in Spanish?	Los lunes. "Los lunes trabajo" (I work on Mondays). No word for "on" is needed.
"January to June" in Spanish?	Enero, febrero, marzo, abril, mayo, junio. Months are lower case in a sentence.
"July to December" in Spanish?	Julio, agosto, septiembre (also setiembre), octubre, noviembre, diciembre.
"The 3rd of April" in Spanish?	El tres de abril. Dates use cardinal numbers; only the 1st can be el primero de mayo (el uno de mayo is common in Spain).
"It's one o'clock" vs "it's three o'clock" in Spanish?	"Es la una" (singular, because una agrees with hora). "Son las tres" (plural for every other hour).
"It's half past two" in Spanish?	"Son las dos y media."
"It's quarter past four" and "it's quarter to five" in Spanish?	"Son las cuatro y cuarto." "Son las cinco menos cuarto" (literally five minus a quarter).
"At what time...?" and "at eight o'clock" in Spanish?	"¿A qué hora...?" / "A las ocho." "¿A qué hora empieza la clase?"
"At nine p.m." in Spanish?	"A las nueve de la noche." With a clock time use de la mañana, de la tarde, de la noche; without one, por la mañana.
"Today, yesterday, tomorrow" in Spanish?	Hoy, ayer, mañana. "Mañana por la mañana" means tomorrow morning.
"The week, the month, the year" in Spanish?	La semana, el mes, el año. Keep the ñ in año: ano is a different, very rude word.
"Last week" and "next month" in Spanish?	La semana pasada. El mes que viene (or el próximo mes).
"How old are you?" and "I'm twenty" in Spanish?	"¿Cuántos años tienes?" "Tengo veinte años." Age uses tener, not ser.