cero 0 zero
uno 1 one
dos 2 two
tres 3 three
cuatro 4 four
cinco 5 five
seis 6 six
siete 7 seven
ocho 8 eight
nueve 9 nine
diez 10 ten
once 11 eleven
doce 12 twelve
trece 13 thirteen
catorce 14 fourteen
quince 15 fifteen
dieciséis 16 sixteen
diecisiete 17 seventeen
dieciocho 18 eighteen
diecinueve 19 nineteen
veinte 20 twenty