bought by my mom是过去分词短语,用作后置定语,相当于被动语态的定语从句,即:I really like this dress bought by my mom. = I really like this dress that was bought by my mom.
▲过去分词短语作定语既可以是限制性的也可以时非限制性的。例如:
The suggestion (that / which was ) made by the expert was adopted by the manager. 专家提出来的建议被经理采纳了。
The books, (which was) written by Lu Xun, are popular with many Chinese people. 这些书是鲁迅写的,受到了许多中国人民的喜爱。
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