What does 'algunas' mean? if it here it is in a sentence: algunas fiestas se celebran en la case de la familia. who ever answers this will get a , brainiest answer and 20 points

"algunas" is formed with "algun+a+s"
where the "a" is the feminine and the "s" is plural.

Algun means "some": algun pais: some country, algun amigo: some friend

so algunas means some for femininine plural: some parties.

party, Fiesta is feminine in spanish, so you need a feminine version of algun.

and the sentence means: some parties are celebrated in the house (casa not case!) of the family

well, in this context, fiesta can also be a "celebration" or "holiday", not only a party

so it means "some unspecified ones"

Algunas means some  the sentence says Some parties are celebrated in my family house.

Bi’m pretty sure i am pretty fluent in spanish so it should be right

In spanish a lot is mucho or demaciado