All parents take pride in their kids especially when they are seen to be improving.

问题描述:

All parents take pride in their kids especially when they are seen to be improving.
"they are seen to be improving"这句怎么理解?我知道意思,就是没办法理解它的语法——为什么可以这么说?

被动语态啊,而且是进行式强调现场感
所有的父母都为孩子感到骄傲,尤其是在看着他们进步时.