Foreigners often make some strange mistakes in Chinese when they study the most difficult language--- ---Chinese. We try to analyze typical sentences to correct these errors.

         Nín yào jǐ pínɡɡuǒ?
False: 您要几苹果？
         Nín yào jǐ ɡè （ɡōnɡjīn） pínɡɡuǒ?
True: 您要几个（公斤）苹果？

用“几”询问数量时，“几”与中心语之间一定要用量词。“苹果”的计量单位可以用“个”，也可以用“公斤”。
There must be a measure word between 几 and its head word in a sentence using 几 to inquire number. Apples are usually calculated in units of 个 or 公斤, so either 个 or 公斤 should be added before 苹果.