¿Ningún o ninguno/a?

[irmamar]

"Unos" (always in plural) is used with the same meaning of "algunos", just in some ocasions.

"Unos" (siempre en plural) tiene el mismo significado que "algunos", sólo en algunas ocasiones (here I can't use "unas")

Unos niños corren = algunos niños corren.

But if I know there are ten children, I should use "algunos":

Hay diez niños, algunos (de ellos) están jugando.

But if I compare two groups I could use "unos":

Hay diez niños, unos están jugando, otros están viendo la tele.
or Hay diez niños, algunos están jugando, otros están viendo la tele (o los demás están viendo la tele)

[EmpanadaRica]

Ok thank you! :-)
Let me try to find the English equivalent to make sure I understood this distinction correctly. If something is not right, kindly correct me :)

1. The words ' unos' and ' algunos' can be used interchangeably if you have no more specific information about the quantity and/or are saying something in general about it.('Some')

2. Otherwise, of you wish to be more specific and single out a part of this group, you must use 'algunos/algunas' ('Some of the...') to say more about this subgroup, or use 'unos/unas' twice to give more specific information on both subgroups (' Some..., some....').

iiMuchas gracias por explicarlo!!:thumbsup:

[irmamar]

Ok thank you! :-)
Let me try to find the English equivalent to make sure I understood this distinction correctly. If something is not right, kindly correct me :)

1. The words ' unos' and ' algunos' can be used interchangeably if you have no more specific information about the quantity and/or are saying something in general about it.('Some')

2. Otherwise, of you wish to be more specific and single out a part of this group, you must use 'algunos/algunas' ('Some of the...') to say more about this subgroup, or use 'unos/unas' twice to give more specific information on both subgroups (' Some..., some....').

iiMuchas gracias por explicarlo!!:thumbsup:

1. yes;)
2. Yes, but you can't say "unos/as" twice, but you say "some... and the others...":
Unos cantan, otros bailan
Algunos comen, otros duermen.

Remember, you can use unos/algunos interchangeably. Just remember to use "algunos" if you don't add what the others are doing (being, etc.)

Tengo cien libros, algunos son buenos (if I said "unos son buenos" I should end the sentence: "los otros son malos").
Tengo cinco hermanos, algunos son rubios (unos son rubios, los otros pelirrojos)

Anyway, I'm sure this is not an exam question ;)