Simplify the following text for a Grade 4 native English-speaking person.
Original: JanÃ Ä ek expressed his painful feelings for his daughter in a new work , his opera JenÅ fa , in which the suffering of his daughter became JenÅ fa 's .
Simplified: JanÃ Ä ekâ s spent several years writing his opera JenÅ fa . By the time he was finishing it his daughter had died .