Who speaks Spanish
the main language of:
Spain, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Cuba, Dominican Republic, Puerto Rico, Colombia, Venezuela, Ecuador, Peru, Bolivia, Paraguay, Chile, Argentina, Uruguay
it’s also spoken in:
USA (some southern states are effectively bi-lingual), parts of Morocco, Equatorial Guinea, Andorra, the Philippines
and the number of mother-tongue speakers worldwide is:
N.B. The language we call “Spanish” is also known as "Castilian" ("castellano") to distinguish it from the other languages used in Hispanic countries today.