When we must use Spanish and when Spaniard?.
When we must use Spanish and when Spaniard?. Which one is ok?: "The Spanish one won the race" "The Spaniard one won the race"

Question

When we must use Spanish and when Spaniard?.
When we must use Spanish and when Spaniard?. Which one is ok?:  "The Spanish one won the race" "The Spaniard one won the race"

Answer

Spanish is an adjective.

It's possible to say 'Spanish one', but not usually for a person. You would probably say, for example:

'The Spanish athlete won the race' 
or
 'The Spanish runner won the race'.

Spaniard is always a noun. (sustantivo)

So you could say 'The Spaniard won the race'.

Note that you can say 'the Spanish' but this has a different meaning. If you say 'the Spanish' you are referring to the Spanish nation as a whole. For example, 'The Spanish tend to eat dinner fairly late in the evening'.