Hi again, and welcome back to Just Answer.
Sentir and sentirse are both translated to mean 'to feel'. Sentir usually refers to feeling emotions, but it can also refer to physical feelings/sensations.
Sentir is very often used in its 'reflexive' form, 'sentirse' and describes how a person is feeling.
Here are some examples of sentir, to describe feelings of emotion and sensation:
Ella siente felicidad por ser madre--She feels happy about becoming a mother.
Puedo sentir pasos en el techo--I can hear (feel/sense) footsteps on the roof. (here it is used in the infinitive form)
Siento que algo malo viene--I feel that something bad is coming.
Sentirse is typically used to describe a feeling of pain in a body part. Example:
Me siento dolor de la cabeza.--I have a headache (I feel pain in my head)
Ella no se siente bien; tiene dolor del estómago--She doesn't feel well; she has a stomachache.
Used by itself, sentir can be used to mean feeling sorrow or regret. A commonly used expression which I'm sure you've heard/used, is 'Lo siento' and/or 'Lo siento'--I'm sorry. and 'Lo siento mucho'--I'm very sorry.
Of course you have to keep in mind that both sentir and sentirse are classified as irregular verbs because they are e to ie stem changing verbs.
Please let me know if you need any additional information by clicking 'Reply
If you have found this answer helpful, please click 'ACCEPT', as this is the only way I am compensated for assisting you today (although you have made a deposit/have a subscription, no payment is released to the Expert until you click on 'Accept').
Positive Feedback and Bonuses are always welcomed and appreciated.