物主代詞不可與 a, an, this, that, these, those, some, any, several, no, each, every, such, another, which等詞一起前置，修飾一個名詞，而必須用雙重所有格。 公式爲：a, an, this, that 物主代詞不可與 a, an, this, that, these, those, some, any, several, no, each, every, such, another, which等詞一起前置，修飾一個名詞，而必須用雙重所有格。
公式爲：a, an, this, that +名詞+of +名詞性物主代詞。
如：a friend of brother of his.