Why is it “la mano” and not “el mano” in Spanish?

Beginners learn a handy rule: words ending in -o are usually masculine (el libro, el coche). But mano (“hand”) breaks it. It ends in -o yet is feminine, so you say la mano, not “el mano.” Adjectives follow the gender, so it is la mano derecha (“the right hand”), not “derecho.” It is one of the most common exceptions, so it is worth fixing in memory early.

From the clip’s body-parts list: Mano, la mano. A few other everyday words break the same rule, like la foto (photo) and la moto (motorbike) — both feminine, both shortened from longer feminine words (fotografía, motocicleta).