Here's why:
* Dominican Spanish is the official language. Almost everyone in the country speaks it, and it's the language used in education, government, and daily life.
* There are no reliable statistics: While there are population estimates, there's no comprehensive census specifically tracking language fluency.
* Some people might speak other languages: While Spanish is dominant, some people may speak other languages, like Haitian Creole or English, especially in border areas or among certain communities.
Therefore, it's safe to say that the vast majority of the Dominican Republic's population speaks Spanish.