General Grammatical Rule:
Nouns ending in "-a" are typically feminine in Spanish. This rule applies to a vast majority of Spanish nouns, and "la pizarra" is no exception.
Exceptions:
While the "-a" ending usually indicates a feminine noun, there are some exceptions, such as:
* Nouns ending in "-ía" or "-ía" (e.g., "el día," "el sofá").
* Some nouns that are masculine despite ending in "-a" (e.g., "el mapa," "el drama"). These are typically learned through memorization or specific contexts.
Therefore, "la pizarra" is feminine because its ending in "-a" follows the general grammatical rule for feminine nouns in Spanish.