I have never heard a person referred to as "a Spanish" I think it maybe a technically correct way to refer to someone from Spain, but I've never heard it out loud in conversation. And, "a Spaniard" reminds me of 15th century Spanish explorers. Upon reflection, I think I normally use a a phrase when talking about people from Spain. For example, I taught a group of women from Spain last year in Toronto. Are you from Spain? NOT: Are you a Spanish? Are you a Spaniard?

There are three ways to describe someone as coming from Spain. 1. He is Spanish. 2. He is a Spaniard. 3. He is from Spain. Option 2 is relatively uncommon in American English.

According to the Cambridge dictionary : .- Spanish: from, belonging to or relating to Spain. .- Spaniard: a person from Spain.

Spaniard is the noun and Spanish is the adjective (unless of course you are referring to the language when Spanish is a noun). We don't say "a Spanish" in English because we can't be specific about the noun it describes in the way that one is able to in French (une/un française/français). For this reason we say a spaniard to describe a person. It's more common to say "a spanish person". This is a common mistake, so don't worry. The others who have commented about spaniards being the people who colonised the americas are getting "spaniard" confused with the conquistadors.

Thanks :D