一个英语句子the dress which i bought 和 the dress which was bought

一个英语句子
the dress which i bought 和 the dress which was bought by me 这个两句表达的意思是不是一样?这里的which可不可以换成of 对于定语 怎样判断用什么样的介词 on in of which that 定语对于修饰词是都做主语吗

1.the dress which i bought 和 the dress which was bought by me 这个两句表达的意思一样,但是通常人们说
the dress which i bought ,很少说 the dress which was bought by me,因为 the dress which was bought by me 中
定语从句 which was bought by me 是被动语态,而被动语态在科技英语中和动作的执行者不明确、不知道、不重要时才用,但是在这句话bought的主语是我(I),主语很明确,所以通常交流中不会用被动态,所以很少说 the dress which was bought by me.当然句子　the dress which was bought by me　从语法上讲没有错误..
2.the dress which i bought 和 the dress which was bought by me 这个两句中的which不能用of代替which,因为of 是介词,表示名词之间或名词与代词之间的关系.例如:啊a friend of mine "我的一个朋友",of 连接的词是名词 a friend 和 名词性的物主代词 mine ,表示"我的(mine)" "一个朋友(a friend)",当然　of mine 作定语修饰　a friend,of mine 是介词短语作定语.而which 是关系代词,引导定语从句作定语,并且which在定语从句中作主语或者宾语.即which 是在一个从句修饰一个名词或者修饰代词时才用.　例如:　the dress which i bought 中,　which引导定语从句：which i bought　修饰the dress ,which　还在从句中作bought　的宾语.再如:　the dress which was bought by me 中,which引导定语从句:which was bought by me 修饰　the dress ,which　还在定语从句中作主语.而of 不能引导从句,所以这里的　which　不可以换成 of .
3.当定语从句前面需要用介词时,选择什么介词,有两个依据:(1).根据定语从句修饰的哪个词(名词或者代词,通常被称为先行词)来决定,the bookshelf on which he put the English-Chinese dictionary “他放英汉词典的那个书架”.这里用介词 on 是因为"将...放在书袈上"　应该用介词 on .所以选择介词　on,而不能用其它介词.(2).根据介词与定语从句中的动词的搭配关系决定:例如：the book from which I learned a lot "这本我从中学习到很多知识的书",　这里用介词 from 是因为:from 与learn搭配成为词组:learn...from,“从...学习;向...学习”,所以定语从句前面的介词选择：from,而不能用其它介词.
4."定语对于修饰词是都做主语吗":我如果没有理解错您提出的这个问题,现在回答如下：定语对于修饰词是都作定语而不是作主语.
由于我的电脑输入汉字出现问题,所以输入较长时间汉字才回答了这个问题,