efectivo noun or adjective

Question

At first glance, I thought efectivo is an adjective (meaning effective) but it actually means cash. Is there an obvious ending to nouns in spanish like there is in english?

Inma Sánchez · Accepted Answer

Hola Shafagh
efectivo is both, an adjective meaning "effective" and a noun meaning "cash".
For example:

Este régimen de comidas es muy efectivo. (adj)
This diet is very effective. 
Usted debe pagar en efectivo.(noun)
You must pay cash.

There is a general rule for Spanish adjectives; regular adjectives end in -o (masculine) and -a (feminine), but there are lots of exceptions and other endings too. I'm afraid there is a lot of memorising there.
Saludos
Inma