Grifo vs. llave vs. canilla
The Spanish language presents a rich variety of vocabulary as it is spoken in different regions of the world. The words grifo, llave and canilla all translate to faucet or tap in English, but their usage can vary depending on locale.
Grifo
A2The most universal term for faucet or tap in Spanish.
El grifo está goteando.
(The faucet is dripping.)
Cierra el grifo cuando te cepillas los dientes.
(Close the tap when you brush your teeth.)
Llave
B1While also means key, this Spanish word is mostly used in many parts of Latin America for faucet or tap.
La llave del agua está rota.
(The water faucet is broken.)
Por favor, cierra la llave.
(Please, close the tap.)
Canilla
B2Canilla is from Rioplatense Spanish dialect, used primarily in Argentina and Uruguay for a faucet or tap.
Hay que reparar la canilla de la cocina.
(We need to repair the kitchen faucet.)
La canilla está abierta, por eso hay tanto ruido.
(The tap is open, that's why there is so much noise.)
Summary
Grifo, llave, and canilla are three terms used to denote a faucet or tap in different regions of the Spanish-speaking world. While grifo is universally understood, llave tends to be used in Latin America and canilla is more typical in Argentina and Uruguay.