关于there be句型They are some boys playing on the play ground.这句

一、There is/are 是there be 句型,be动词的选择要与后面的主语保持一致,如果是多个主语时,谓语动词要遵循“就近原则”.
二、There be句型的基本用法是表示“某地(或某时)存在有某人(或某物),而并非某地(某人、某物或某时)拥有什么东西”,其形式为“There be＋代词或名词(短语)＋地点/时间状语”.(其实质句式为倒装句)这里there是引导词,没有词义,be是谓语动词,代词或名词(短语)是主语.be要与主语保持人称和数的一致.否定句是在be后加not；一般疑问句是将be放在句首；反意疑问句中的简短问句是由“be(或其否定式)＋there”构成.例如：
1.There is a desk and two chairs in the room.
(紧挨着be动词的主语是a desk,是单数,故be的形式要用is)
2.There aren't two chairs and a desk in the room.(否定句)
3.Is there anything wrong with your ears?(Yes,there is/No,there isn't.)
4.There wasn't a meeting yesterday,was there?(反意疑问句)
除此之外,还有一个重要句式“有某人在做某事”,要用“There be＋sb.＋doing sth.＋地点/时间状语”.例如：
There are several children swimming in the river.河里有几个孩子在游泳.

是状语。是倒装。
Some boys are playing on the play ground .