If you look up ‘medio’ and ‘mitad’ in the dictionary you might think these are perfect synonyms because they have the same English equivalent; however, they have some differences in use.

Mitad is a female noun that we use to talk about 50% of something. We use ‘mitad’ to refer to two equal parts of a whole and it’s typically followed by the prepostion ‘de’. ‘Mitad’ can also be used an adverb.

• Comimos la mitad de la torta y guardamos la otra mitad para mañana. We ate half the cake and we saved the other half for tomorrow.
• ¿Qué has hecho? ¡Tienes la mitad de la cara cubierta de barro! What have you done? Half your face is covered in mud!
• Los centauros son criaturas mitológicas mitad hombre y mitad caballo. Centaurs are mythological creatures half man, half horse.

 

On the other hand, ‘medio’ is an adjective so it always has to agree with the noun it’s modifying (medio/media). We use ‘medio’ to refer to a half quantity of something, but it can also be used to talk about distance, time, length, etc.

• Quiero medio kilo de naranjas, por favor. I would like half a kilogram of oranges, please.
• Estamos a medio camino entre las montañas y la playa. We’re half way between the mountains and the beach.
• Vimos media película y nos quedamos dormidos. We watched half the movie and we fell asleep.
• Hablaron por media hora en el teléfono. They spoke for half an hour on the phone.