In Spanish, the verbs sentir and sentirse both relate to the idea of feeling, but they are used differently and convey distinct nuances. Understanding when and how to use each is essential for expressing emotions and sensations accurately.

Sentir: Typically used as a transitive verb, meaning "to feel" or "to sense" something (a sensation, an emotion, or even a physical stimulus). It often requires a direct object.
Sentirse: Is the reflexive form of sentir and is used to express how someone feels internally—usually referring to emotions or states of being. It’s used intransitively and focuses on the subject’s own feelings.

Sentir: To Feel, To Sense

Sentir expresses the act of perceiving or experiencing something, and it usually needs a direct object (what is felt).

It can be used for both physical sensations and emotions.
Commonly appears with nouns or clauses that describe what is being felt.

Sentir in Context

Sentir + [direct object]: Me siento el frío. (I feel the cold.)
Sentir + [emotion]: ¿No sientes alegría? (Don’t you feel joy?)
Sentir + que + [clause]: Siento que no vas a venir. (I feel that you’re not going to come.)

Sentirse: To Feel (Oneself), To Be (Emotionally/Physically)

Sentirse is used when talking about how someone feels internally—emotionally or physically—and is always reflexive.

Used only when referring to the subject’s own feelings/states.
Typically used with adjectives or adverbs, not nouns.

Sentirse in Context

Sentirse + [adjective]: Me siento cansado. (I feel tired.)
Sentirse + [adverb]: ¿Te sientes bien? (Do you feel well?)
Sentirse + [noun adjective phrase]: Se sienten felices. (They feel happy.)

When do you use 'sentirse'?

To express internal feelings or states

With adjectives

With direct objects

To express outward sensations

'Sentirse' is used to express internal feelings or states and is used with adjectives.

Comparing Sentir vs Sentirse

Aspect	Sentir	Sentirse
Type	Non-reflexive	Reflexive
Meaning	To feel/to sense (something)	To feel (oneself); to be (in a state)
Usage	Needs direct object or clause	Used with adjectives; no direct object
Examples	Siento dolor.	Me siento mal.
What’s Expressed	External sensation/emotion	Internal emotion/state

Conclusion

Use sentir when you can identify or attach what is being felt (a thing, a sensation, or a situation).
Use sentirse when you talk about how someone feels internally, focusing on their emotional or physical state.
Mastering sentir and sentirse unlocks a richer, more precise way to express feelings in Spanish.

Which is the main difference between 'sentir' and 'sentirse'?

Sentir is reflexive; sentirse is not.

Sentir expresses external feelings, while sentirse expresses how someone feels internally.

Both are used interchangeably