In which Caribbean country is Spanish primarily spoken, reflecting its colonial history?

Cuba is primarily a Spanish-speaking country due to its colonial history, which traces back to its time as a Spanish colony from the late 15th century until 1898. The Spanish influence has deeply permeated the culture, language, and society of Cuba, making Spanish the dominant language spoken by the vast majority of its population.

In contrast, while Belize is located in Central America and has a history involving British colonization, it recognizes English as its official language, although Spanish is also commonly spoken due to geographic proximity to Spanish-speaking countries. Guatemala, despite being predominantly Spanish-speaking today, was influenced by various indigenous languages and cultures, stemming from its rich Mayan heritage. The Dominican Republic shares its colonial history with Cuba, as both were formerly part of Spanish territories; however, the emphasis on Cuba in the context of the question leads to its selection as an example reflecting Spanish as the primary language.

The Dominican Republic indeed also speaks Spanish, but with Cuba's historical prominence and cultural influence, it is generally recognized first in discussions about Spanish-speaking Caribbean nations.