例题:The teachers are talking about the problem discussed at the meeting.为什么discussed 不用 was discussed.请详细说明过去分词与被动式的区别!!
热心网友
被动式需要主语部分。过去分词不需要的。如果这个句子用被动式，必须补齐从句里的主语以及系动词The teachers are talking about the problem ___that was __ discussed at the meeting去掉 that was ，就变成简洁的分词形式了。
热心网友
discussed at the meeting在这句话中用作修饰the problem，discussed和被动式无关！