有关被动语态的几个问题：
1）“be + 过去分词” 并非都是被动语态，系动词 be， feel， seem，look，等词后面的过去分词已转化为形容词，作表语用，表示某种状态。
i‘m interested in mathematics.
我对数学感兴趣。
he seems unsatisfied with his work.
他看起来对他的工作不满意。
we are determined to catch up with the developed countries.
我们决心要赶上发达国家。
the song is called “don‘t forget me”。
歌曲的名字叫“勿忘我”。
2）某些动词用主动语态来表示被动含义。
the food tastes good.
食物很香。
it smells strange.
这有怪味。
the stone feels very cold.
石头摸起来很冷。
the woman‘s clothes sell well.
女装卖的快。
3）一般情况下，及物动词才能构成被动语态，但有些不及物动词组成短语后，也可构成被动语态。
he was looked down upon because of his egoism.
他因自私而受人冷落。
the children were taken good care of in the the orphanage.
孩子们在孤儿院受到了良好的照顾。