Cheerful = Noticeably happy and optimistic; Causing happiness by its nature or appearance; full of cheer; in good spirits; pleasant; bright; hearty or ungrudging
Synonyms: merry, jolly, joyful, happy, glad, blithe, cheery.
Example – The staff here is friendly and cheerful.
Usage in Sentence: Cheerful in, not of.
Don’t say: Tina is very cheerful of nature.