Final answer:
The most commonly eaten food for breakfast in Spanish is pan tostado (toasted bread).
Step-by-step explanation:
In Spanish, the most commonly eaten food for breakfast is pan tostado, which means toasted bread. It is a simple and popular choice, often served with butter or jam. Other options mentioned, like pizza or hamburguesa (hamburger), are not typically eaten for breakfast in Spanish-speaking countries.
Learn more about Breakfast food in Spanish