Spanish-Numbers rules, on pg 16
rule 4
The Spanish equivalent of both there is and there are is hay. use ¿Hay...? to ask is there...? or are there...? use no hay to express there is not or there are not.
rule 2
The forms uno and veintiuno are used when counting(uno, dos, tres...veinte, veintiuno, veintidós...). they are also used when the number follows a noun, even if the noun is feminine: la lección uno.
rule 1
The number uno (one) and numbers ending in -uno, such as veintiuno, have more than one form. before masculine nouns, uno shortens to un. before feminine nouns, uno changes to una. un hombre- veintiún hombres una mujer- veintiuna mujeres
rule 3
To ask how many people or things there are, use cuántos before masculine nouns and cuántas before feminine nouns.