these 是代词,意思是“这些” These flowers are beautiful.这些花很漂亮.
they 人称代词,意思是“他们” My friends are playing football,and they want us to play too.我的朋友们在踢足球,他们想要我们也（一起）踢.
they也可以形容事物
例如,There are many birds in the tree.They are pretty.
(这里的they 形容birds)
英文词用法我知道these是形容事物,they是人,那么they可以形容事物吗