He used to be a linguist but he turned a good teacher later.
turn后接名词作表语,如果名词前有形容词修饰,要不要加不定冠词?
turn后接名词作表语时,不管名词前是否有形容词修饰,都不要加不定冠词。
表示某个人的职业,不用turn
He used to be a linguist but became a teacher later.