Usar vs. utilizar vs. emplear

The Spanish verbs 'usar', 'utilizar' and 'emplear' all mean 'to use' in English. While they can often be used interchangeably, there are some subtle differences in usage and connotation.

Usar

'Usar' is the most common verb for 'to use'. It is generally used in everyday conversation and in a more informal context.
Voy a usar el coche para ir a la tienda esta noche.
(I am going to use the car to go to the store tonight.)
Si vas a usar mi ordenador, no borres ninguno de mis archivos.
(If you're going to use my computer, don't delete any of my files.)

Utilizar

'Utilizar' is also commonly used, but it is slightly more formal than 'usar'. It is often used when referring to tools or resources.
Para hacer ese plato tienes que utilizar una cazuela grande.
(To prepare that dish you have to use a big pot.)
He utilizado un ordenador para calcular el resultado.
(I used a computer to calculate the result.)

Emplear

'Emplear' is the most formal verb of the three, usually used in professional or academic contexts.
"Síntesis" es un método que se suele emplear en el campo académico.
('Synthesis' is a method usually employed in academia.)
Se puede emplear este algoritmo para solucionar el problema de manera eficiente.
(You can employ this algorithm to solve the problem efficiently.)

Summary

'Usar', 'utilizar', and 'emplear', while all translating to 'use', carry varying degrees of formality and different connotations. While they can often be used interchangeably, it's important to note their differing tones in daily conversation, written communication, professional settings, and academic contexts.