Alphabet

1. The standard dialect in Spanish is Castilian Spanish.
2. Royal Spanish Academy (RSA) is the governing body of the language.
3. Another is the American Spanish in Mexico and Latin Amercia.
4. The main differences in their pronunciation are: (a) the letter j and the letter g are pronounced as /h/ in American Spanish but /x/ in Castilian Spanish; (b) the letter z and the letter c in front of front vowels /e/ or /i/ are pronounced as /s/ in American Spanish but /θ/ in Castilian Spanish.
5. Spanish alphabet uses the Latin's with 3 additional letters added to the Latin's: ch, ll, ñ, see below:
   
6. "rr" has not been recognized as a letter in Spanish.
7. The letters ch and ll were officially dropped from the Spanish alphabet in 1994.
8. An interactive website for pronunciation of the letters.
9. Declension: infection in pronouns and adjectives for features as number, case, gender and possession.
10. Every noun in Spanish has a gender: either Masculino and Femenino. They are not inflection.
11. Right-branching text alignment.
12. Uses prepositions.
13. Sentence structure in Subject-Verb-Object (SVO); but partially pro-dropped for a subject pronoun, or inferable null-subject, allowing a Verb-Object (VO) sentence structure.
14. English is satellite-framed whereas Spanish is verb-framed.
15. A verb describes both manner of motion and path of motion. A verb in Satellite-framed language shows the manner but use a particle to show the path (e.g. run into). In contrast, a verb in verb-framed language encode the path into the verb (e.g. entrar = go in; salir = go out)
16. Syllable-timed language: each syllable has the same duration regardless of stress.

References:

1. http://www.spanishspanish.com/alfabeto_ipower.html
2. Web article "Spanish language" on Wikipedia
3. Web article "Spanish phonology" on Wikipedia