不是。前者意思是“不是....,而是...”,后者意思是“不仅...,而且...”.例如:Not me but Tom took your books. 不是我而是汤姆拿了你的书。(我没拿你的书,汤姆拿了。)Not only me but also Tom took your books.不仅我拿了你的书,而且汤姆也拿了。
They came here not for money but for the life 他们来这儿不是为了钱而是为了生活不是一个意思