Motivo vs. razón

The Spanish words 'motivo' and 'razón' both broadly translate to 'reason' or 'cause'. However, their usage can vary subtly based on context and idiom. While both words can be used interchangeably in some instances, there are specific scenarios where they are used distinctly.

Motivo

'Motivo' refers more towards the motive or reasons behind an action often related to emotions, objectives or goals. This term is best utilized in contexts planning a task, a celebration, or giving explanations tied to emotional reasons.
El motivo de mi viaje es visitar a mi familia.
(The reason for my trip is to visit my family.)
Por motivo de su cumpleaños, vamos a hacer una fiesta.
(Because of his birthday, we are going to have a party.)
No comprendo el motivo de tu enfado.
(I do not understand the reason for your anger.)

Razón

'Razón' tends to indicate reason in more logical or rational contexts. It's generally used in cases that explain facts, correctness, and logical explanations.
La razón por la que no fui al cine es porque tenía que trabajar.
(The reason why I didn't go to the movies is because I had to work.)
Tiene razón, el examen fue muy difícil.
(You're right, the exam was very difficult.)
La razón de su éxito es su constancia y dedicación.
(The reason for his success is his persistence and dedication.)

Summary

'Motivo' and 'Razón', while similar, are distinguished by their usage based on scenarios. 'Motivo' leans more towards personal motives or emotionally charged situations while 'razón' tends to denote logical or factual explanations.