There is some water in the bottle.水不是一个,为什么是is不是are?

【there be】表示“某处有某物”,这个句型结构中,be动词的变化有两种形式：
1. There is 后面跟单数名词、或不可数名词
例如 There is some water in the bottle. 瓶子里有些水.
water 是不可数名词,所以用 There is...
2. There are 后面跟复数名词
例如 There are some boys on the playground. 操场上有些男孩.
boys 是复数名词,所以用 There are ...