Estricto vs. severo vs. riguroso
The Spanish words estricto, severo, and riguroso can all be translated as strict or severe, but they carry distinct nuances. The word estricto focuses on strict compliance with rules and boundaries without exceptions. The word severo leans toward harshness, sternness, and a lack of leniency, often involving punishment or a serious demeanor. Finally, riguroso emphasizes extreme precision, thoroughness, or intensity, and is frequently used for scientific methods, inspections, or even extreme weather.
Estricto
The word estricto is used to describe a person, rule, or system that demands exact obedience to guidelines without allowing any exceptions.
Mi profesor de matemáticas es muy estricto con la puntualidad.
(My math teacher is very strict about punctuality.)
El exclusivo restaurante de la esquina tiene un código de vestimenta estricto.
(The exclusive restaurant on the corner has a strict dress code.)
Mis padres eran estrictos pero siempre me trataron con mucho cariño.
(My parents were strict but they always treated me with a lot of love.)
El atleta profesional sigue una dieta estricta para prepararse para el torneo.
(The professional athlete follows a strict diet to prepare for the tournament.)
La nueva ley ambiental es estricta respecto a la contaminación del agua.
(The new environmental law is strict regarding water pollution.)
Severo
The term severo describes a person, punishment, or expression that is harsh, stern, and shows a complete lack of indulgence, warmth, or leniency.
El juez del caso impuso un castigo severo al delincuente por sus acciones.
(The judge of the case imposed a severe punishment on the criminal for his actions.)
Su abuelo tenía un rostro severo que a veces asustaba a los niños del vecindario.
(His grandfather had a stern face that sometimes scared the neighborhood children.)
La junta directiva tomó medidas severas contra el fraude interno.
(The board of directors took severe measures against internal fraud.)
La directora me dio una mirada severa cuando hablé durante la ceremonia de graduación.
(The principal gave me a severe look when I spoke during the graduation ceremony.)
El crítico literario escribió una reseña severa sobre la nueva novela del autor.
(The literary critic wrote a harsh review about the author's new novel.)
Riguroso
The adjective riguroso implies strictness combined with extreme precision, thoroughness, or intensity, and is often applied to methods, inspections, or harsh climates.
El equipo de científicos realizó un análisis riguroso de todas las muestras de sangre.
(The team of scientists performed a rigorous analysis of all the blood samples.)
Pasamos por un control de seguridad riguroso antes de abordar el avión internacional.
(We went through a rigorous security check before boarding the international flight.)
Este invierno ha sido especialmente riguroso en las montañas del norte.
(This winter has been especially severe in the northern mountains.)
Para convertirte en un cirujano especializado se requiere un entrenamiento muy riguroso.
(To become a specialized surgeon requires very rigorous training.)
La revista académica tiene un proceso de revisión riguroso para garantizar la calidad de los artículos.
(The academic journal has a rigorous review process to guarantee the quality of the articles.)
Summary
In summary, use estricto when talking about enforcing rules and boundaries. Choose severo when you want to convey a sense of harshness, sternness, or heavy consequences. Opt for riguroso when describing something that is thorough, highly precise, or intensely demanding, such as an investigation or extreme weather conditions.