彼(かの)女(じょ) kanojoは wa約(やく)束(そく) yakusokuを o誠(せい)実(じつ) seijitsuに ni守(まも)っ()た() mamotta。 She faithfully kept her promise. Literal She [topic-は] promise [object-を] faithfully kept. 誠実に (せいじつに, 'faithfully, sincerely') is the adverbial form of the na-adjective 誠実. 約束を守る (やくそくをまもる, 'to keep a promise') is the standard expression. promisespersonality
彼(かの)女(じょ) kanojoは wa約(やく)束(そく) yakusokuを o誠(せい)実(じつ) seijitsuに ni守(まも)っ()た() mamotta。 She faithfully kept her promise. Literal She [topic-は] promise [object-を] faithfully kept. 誠実に (せいじつに, 'faithfully, sincerely') is the adverbial form of the na-adjective 誠実. 約束を守る (やくそくをまもる, 'to keep a promise') is the standard expression. promisespersonality