Sentimiento vs. sensación
While both sentimiento and sensación can be translated as "feeling," they are not interchangeable. The core difference lies in their origin and nature: sentimiento refers to a more complex, lasting emotion originating from the mind or heart, whereas sensación refers to a physical perception from the senses or an immediate, intuitive gut feeling.
Sentimiento
B1A sentimiento is an emotional state of mind. It refers to a complex and often lasting feeling that is processed mentally and emotionally, such as love, happiness, guilt, or gratitude. It's a feeling that comes from the heart or mind.
El sentimiento de gratitud que tengo hacia ti es inmenso.
(The feeling of gratitude I have for you is immense.)
Después de la discusión, me quedó un sentimiento de tristeza.
(After the argument, I was left with a feeling of sadness.)
Hay un sentimiento general de optimismo en el país.
(There is a general feeling of optimism in the country.)
El amor es el sentimiento más poderoso de todos.
(Love is the most powerful feeling of all.)
No podía ocultar su sentimiento de culpa por lo que había hecho.
(He couldn't hide his feeling of guilt for what he had done.)
Sensación
A2A sensación is a physical perception experienced through the senses (like heat or touch) or a more immediate, intuitive impression or gut feeling. It is often a direct and unprocessed reaction to a stimulus. It's a feeling that comes from the body or intuition.
Tengo la sensación de que alguien nos está observando.
(I have the feeling that someone is watching us.)
Al tocar el hielo, tuvo una sensación de frío extremo en los dedos.
(Upon touching the ice, he had a sensation of extreme cold in his fingers.)
Esa película me dejó una sensación de inquietud.
(That movie left me with a sensation of unease.)
La sensación de la arena caliente bajo los pies es muy agradable.
(The sensation of the hot sand underfoot is very pleasant.)
Al bajar de la montaña rusa, tenía una sensación de mareo.
(After getting off the roller coaster, I had a sensation of dizziness.)
Summary
In short, use sentimiento for emotions that you process with your heart and mind, like love, sadness, or joy. Use sensación for physical perceptions from your senses, like heat or pain, and for immediate gut feelings or intuitions, like the feeling of being watched.