Which is preferred: Castellano or Español?

Castellano and Español are actually the same language, the difference is that people in South America is used to call it Castellano and in Central America they call it Español. The name is actually Español Castellano or Español de Castilla, which is the one that is spoken by most of the people in Spain and was brought to Latin America during the time of the conquistadors.

Castillian Spanish is regulated by the Real Academia de la Lengua Española, which authorizes and revises all the dictionaries published, grammar, orthography, semantic and syntactic issues regarding this language. This means that all the Hispanic countries in America speak the same language with the same rules (unlike UK and the US)

Just to let you know there are other types of Spanish besides the one from Castilla, like Catalan, Basque, Aragon, etc. (I think Spain recognizes around 9 languages as far as I remember)

A good question. Let's see now. In Spain there are four languages:

1 - Catalan

2 - Vasco

3 - Gallego

4 - Castellano

As you say correctly, castellano is the common language called español, spoken by all Spaniards and Spanish speakers in general, but the definition of castellano, etc, you will find it only in Spain.

It is very extended the idea of saying español in other countries, instead of castellano. Very seldom will somebody refer to español as castellano outside of Spain. Besides, it is in Spain where you will find the classic language. In other countries what we use is a local variation of the language.

Consider the difference between the British English and the English spoken in Australia, India, Canada, etc

Here's the breakdown:

Castellano (Castillian) is prefered in Argentina, Paraguay, Uruguay, and Spain.

Español (Spanish) is prefered in Central America, Cuba, Dominican Republic, Mexico, and Puerto Rico.

There is an alternation in Colombia, Bolivia, Chile, Ecuador, Peru, and Venezuela.

I have not had much experience to the Argentines, Uruguayans, and Paraguayans, but I do know that in Spain they prefer to use "Castellano." Many non-Castillian speaking Spaniards like Catalans and Basques will insist that using Español is incorrect since Catalan and Basque are also Español.

Also, to share my experience, I've seen a debate on the internet between Spanish speakers (it was a Spaniard vs. Latin Americans) on which is the correct term. Needless to say, they couldn't come to a consensus. The Spaniard insisted that Castellano was correct while the Latin Americans insisted that Español is.

Check out my source for more information.

Well Castellano and Español is the same... are two different ways to name the same language.

To explain the origin of both names, we have to travel in History, Spain, as we know it today, exist since 1492 (same date of America discovering) when the re-conquest finished, until then, it was formed by 5 kingdoms, Castilla, Leon, Aragon, Navarra and Granada (which was Muslim). When all the kingdoms were united under one government Castilian or Castellano was chosen as the official language (although the rest of languages exists yet) and it was called Spanish or Español, so, it's the same language with two different names...

As Esther C said, it's all in History. "Spanish" language was born in the Kingdom of Castille during the middle ages. It was known as Castellano. Once the reconquest finished and the different Spanish kingdoms (Crown of Castille, Crown of Aragon and Kingdom of Navarre) were united under one dinasty, the Castellano language prevailed and became to be known simply as Spanish.

There's no diference between spanish and castellano. They're just two diferent terms for the same language. Use the one you like the most, it doesn't matter.

Well, Im Mexican and here we speak spanish, I think that when they say that In spain the people speak Castellano, they mean that they pronounce it different, specially, the words with "S", cuz, they pronounce them as if they have a problem with their tonges, jeje, they make a long TH sound, hard to write down.

Hope I was useful.

Y que la fuerza te acompañe

y = x^3 + 3x^2 + 2x Take instantly ahead component x out: y = x * ( x^2 + 3x + 2) Now treatment the quadratic equation x^2 + 3x + 2 and factorize or you want to apply magic: The sum of all even coefficients is reminiscent of the sum of the strange coeffients, so one root is -a million. The synthetic from both roots is two. so 2d root is -2. both way you receives: y = x * (x+a million) * (x+2)

is almos like a synonim but we translate literaly spanish like the one in spain with diferent words, but castellano and spanish is almost the same, u can say that is more formal say castellano

Mexicans speak Spanish....people in places like Spain & Venezuela speak Castillano. It is all Spanish from what I understand...just slightly different ways of pronouncing things. Castillano words have a lot of "th" sounds in them. There is a different accent.