Añadir vs. agregar vs. sumar

When discussing the concept of adding in Spanish, three verbs can be used: 'añadir', 'agregar', and 'sumar'. While all three relate to the addition of items or quantities, they are used in different contexts and possess nuanced meanings.

Añadir

'Añadir' is a verb that generally means to append or to put something extra into what already exists. It can be used both in tangible and intangible contexts.
Añade sal al guiso, por favor.
(Please add salt to the stew.)
Voy a añadir un capítulo más al libro.
(I am going to add one more chapter to the book.)
Después de reflexionar, quiso añadir algunos detalles a su argumento.
(After reflecting, he wanted to add some details to his argument.)

Agregar

'Agregar' often conveys the same idea as 'añadir', implying the action of including or inserting an additional element or component into a group or collection. It is commonly used in both formal and informal contexts.
Puedes agregar tu nombre a la lista si quieres asistir al evento.
(You can add your name to the list if you want to attend the event.)
El chef decidió agregar una nueva especia para mejorar el sabor del plato.
(The chef decided to add a new spice to enhance the flavor of the dish.)
Para completar la inscripción, agrega tu firma al final del documento.
(To complete the registration, add your signature at the end of the document.)

Sumar

'Sumar' specifically refers to performing arithmetic addition or combining quantities, but it can also be used metaphorically to talk about contributing or increasing an abstract quality or quantity.
Si sumas 10 y 15 obtienes 25 como resultado.
(If you add 10 and 15, you get 25 as a result.)
Su experiencia suma mucho al equipo de trabajo.
(His experience contributes a lot to the team work.)
Cada pequeño esfuerzo suma en la lucha contra el cambio climático.
(Every small effort adds up in the fight against climate change.)

Summary

While 'añadir', 'agregar', and 'sumar' share similarities in their denotations related to adding, they differ contextually. 'Añadir' typically means appending elements within various contexts. 'Agregar' often involves including additional items into a set or collection and is somewhat interchangeable with 'añadir'. In contrast, 'sumar’ specifically relates to arithmetic operations or abstract contributions that enhance or increase existing quantities or values.