为什么是It seemed that 不是It is seemed that?为什么it作形式宾语只能说I found

第一个it seemed that 后面接的是表语,这个结构是主系表结构
而第二个It is seemed that 后面接的是句子真正的主语,it做的是形式主语,真正的主语在that后面.
再问： 那是说It seemed that the boss was satisfied with the plan.还是It is seemed that the boss was satisfied with the plan？
再答： 都对
再问： 这两种的成分不一样吧，你能分析下两种的成分吗？