She is, by nature, a sunny, positive kind of person. 她本性是那种乐观开朗、积极向上的人。
He's a plumber by trade. 他的职业是水暖工。
She was, by profession, a lawyer. 她的职业是律师。
He is cautious and risk-averse by nature.
A dentist by profession, she was active in local politics in the 1980s.
A carpenter by trade, he had always been interested in conservation.
See also: by preposition