Let's take a look at a pair of words that are commonly confused by English learners: felt and fell.
Felt is the past tense and past participle of the verb 'feel'.
She felt better after a good sleep.
I haven't felt this sick for a long time.
Fell is the past tense of the verb 'fall'.
I broke my arm when I fell off the horse.
She tripped and fell down the stairs.