Usage patterns
一生懸命に〈動詞〉to do something with all one's might
She studied as hard as she could for the exam.
一生懸命な〈人〉a person who always tries their hardest
He's the kind of person who gives his all at everything he does.
一生懸命に生きるto live one's life to the fullest, giving it one's all
My grandmother has always lived her life giving everything she has.