The answer is:
No, yo no se
When you're talking about nonspecific things.
it's like (a) and (an) in english.
uno is for singular masculine.
una is for singular feminine.
unos is for plural masculine.
unas is for plural feminine.
1) Vincent y Monica están cansados.
Cansados is plural for cansado/a
4) Paloma está enamorada con su novio.
Enamorada is singular feminine
5) Los abuelos de Irene están contentos.
Contentos is plural for contento/a
Hope this helped :)
