Banhar vs. dar banho
While both banhar and dar banho relate to the act of bathing, they are used in very different contexts. Dar banho is the standard, everyday phrase for washing a person or animal, while banhar is more formal, literary, or used to describe immersion, coating objects, and geographical features.
Banhar
B1This verb implies immersing something in liquid, covering a surface, or wetting something. It is frequently used in culinary contexts (to coat food), geography (rivers flowing by cities), or literary contexts (light filling a room). When used for people, it often sounds more technical, medical, or formal.
O rio Amazonas banha vários países da América do Sul.
(The Amazon River bathes several countries in South America.)
Você deve banhar o biscoito no chocolate antes de servir.
(You should dip the cookie in the chocolate before serving.)
A luz do sol banhava todo o escritório naquela manhã.
(Sunlight bathed the whole office that morning.)
A enfermeira vai banhar a ferida com uma solução antisséptica.
(The nurse will bathe the wound with an antiseptic solution.)
Dar banho
A1This is the most common and natural way to say you are washing a child, a pet, or someone unable to wash themselves. It focuses on the active routine of hygiene.
Preciso dar banho no cachorro porque ele rolou na lama.
(I need to bathe the dog because he rolled in the mud.)
O pai foi dar banho no bebê antes de colocá-lo no berço.
(The father went to bathe the baby before putting him in the crib.)
Ela ajuda a dar banho na avó que está doente.
(She helps bathe her grandmother who is sick.)
Eles cobram muito caro para dar banho e tosar o cão.
(They charge a lot to bathe and groom the dog.)
Summary
Use dar banho when performing the daily hygiene task of washing a child, pet, or patient. Use banhar when describing rivers flowing through land, coating food in liquid, or washing specific body parts in a medical context.