[SOLVED] [OPEN DISCUSSION] Castilian vs Latin American Spanish

Spain conquered South America in the XVI century after its discovery. In America people have learnt the language of their colonisers, but because of the distance and the slow loss of this big Empire, American Spanish and Castilian Spanish developed differently:
-American Spanish simplified the sound of the C from /θ/ to /s/ (this is known as seseo) and kept some words which are now considered ancient in Spain. Plus American Spanish was influenced by the aboriginal languages of South America which provided words for things that didn't exist in Europe.
-European Spanish is very conservative and didn't accept words from other languages like American Spanish did (especially from English), so it needed to create new words for things that in American Spanish were expressed with foreign words.

I hope I've answered to your question

I forgot to mention autobús (bus in Spain) and guagua (in Cuba) or colectivo (in Argentina) ahah

I learned Spanish in Latin America and what confuses me most in the European Spanish is the verb conjugations for 2. person plural. In Latin America they don't use "vosotros", they always use "ustedes", even among friends.
So instead of "Vosotros queréis?" it's "Ustedes quieren?"

All this -éis and -áis in European Spanish sound really weird to me...

I see.
Are you moving to Spain to learn?
And yes, there are differences in accents, buut you can learn from videos in youtube, series and movies. That's how I learnt :D
Abt slangs, yes, I am pretty sure there are lots of differences in slangs, as they are based on cultural contexts.

Castillian and Spanish are the same thing: Spanish.
When 'Queen Isabel de Castilla', completed the "Reconquista" at the end of the XV century, her language had grown and extended through the peninsula. Since Spain was then unified, the language, now national, was, eventualy called Spanish. Then, the same language was carried to 'Las Américas".
Now a days, the differences in the spoken language between Spain and Hispano America, are mostly in pronunciation. Number one:
ce - ci, in Spain --> se, si, in Hispano America
za - zo - zu, in Spain --> sa - so - su, en Hispano America.

In Grammar, the most important one is the fact that, in Hispano America, the familiar form 'vosotros', in the verbs, it's not used. It goes like this:
Spain -
Singular Plural
Yo Nosotros
Tú - usted Vosotros - ustedes
él - ella Ellos - ellas

Hispano América
Singular Plural
Yo Nosotros
Tú - usted Ustedes
él - ella Ellos - ellas
These are the pronouns. The thing is that, with the formal "usted/ustedes", the verb is used in third person (not second), and the language, naturally, sounds different.
Aside from this, there are linguistic differences, as it happens within Spain itself, among the different Hispanic countries, or any other country in the world.

The dictionary I use for translations English-Spanish/Spanish-English, is "Diccionario Internacional Simon and Schuster".
There, if there is a difference in the meaning, or use, of a word, in any Hispanic country, it is explained.
And my Spanish dictionary is: 'Diccionario de la Lengua Española'. (International)

Note: I am Castillian, geographycally speaking, and I always say "I speak SPANISH"

Yes, Nestre, you are right: After the 'descubrimiento" and during the 'conquista', most Spaniards In America were from the South, where they 'sesean'. Later on in history, the North emigrated. Cuba was for them "The promised land".

I would probably stay away from the slang spoken in Mexico and or the way they use Spanish. The Spanish spoken in the city is what others refer to as "Neutral Spanish" with no accent whatsoever (or is it really?), compared to the heavy accents in the north and south. The slang is a little harder to grasp, especially when words have more than one meaning, and when two or more are put together they create a whole new meaning haha! The slang usually has a story behind it or is a comparative to something that makes no sense in modern times :) Not only that, but English words are now "Spanishized" (made up word) as in, we add an '(i)ar' at the end of English words and it now becomes a Spanish word. This of course applies to a younger generation, but also to Mexican Americans and their Spanglish (that includes me, but I only do this with family and friends and is viewed as immature/unprofessional at my job).
ex:
hangiar - "hang" + "iar"= to hang out with
textiar - "text" + "iar"= to text

I didn't say that because of what you said Rosa, I'm saying it because even I have a hard time understanding the Spanish spoken in Mexico sometimes, even worse with the slang (depending on the area/state it is spoken). Mexico is a melting pot too, not everyone is simply 'Mexican' there, indigenous people have influenced the language a lot, and that's what makes us a little different :)

The way they speak in Colombia has a huge difference between the costa and, say, Bogotá.
It is like two different countries.
On the costa it is pure Caribbean, in the highlands it is more like Spanish.

Todos ellos en EI Caribe

I think the DarlJoshua's statement about American Spanish simplifying /θ/ to /s/ and Spain not doing it is way off historically. In much of Spain seseo is the norm, and strangely enough the areas in which it is the norm include Westen Andalucía (not low-incom low-prestige rural working class, they have ceceo not seseo, but everyone else) and Las Islas Canarias which are the places rather a lot of the people who colonised the Americas came from. I'm not sure what proportion of people in Spain use both /s/ and /θ/ but I think it's less than 60% (but probably not less than 50%) and it's far less than 10% in the areas from which the Americas were mostly colonised. That sure doesn't seem as if the merging of those two phonemes happened only on the Western side of the Atlantic.
I imagine that by the time the Americas got a significant proportion of new immigrants who either had the two distinct phonemes or used /θ/ for s as well as for z and for soft c the local pronunciation was already pretty much fixed.

I love you, rainymoon, in any language, pero
Ique viva España!