idi
Pizarras
Unas manos is the plural form of "una mano".
Unas clases
It's "unas fotografías."
It's, "las pizarras.
It's never the same. Could be unas, unos, los, las, etc.
masculine: un, unos feminine: una, unas
Unas gomas.
The singular form of "unas libretas" is "una libreta."
The singular form of "unas capitales" is "una capital."
Unos - masculine objects Unas - feminine objects
masculine = un (a/an, singular), unos (some, plural) feminine = una (a/an, singular), unas (some, plural)