不可数名词用三单吗,比如food是用is还是are?

不可数名词一般可视为单数,如Time is money中的time.针对food一词,在The food in the fridge IS not enough一句中用单三,但在These kinds of food WERE never available when she was young中,虽然food为句子的逻辑主语,但语法主语为kinds,kind可数,所以谓语be跟随kind的复数形式kinds变成were.
People一词,取“人”之意时单复数形式相同,指“民族”时复数加s,不可数名词不能冠布丁冠词a和an,“一个人”一般用a person或a man来表示