英语表示名词所有关系有两种形式，一是在名词后加of短语，这种形式多用于无生命的名词后，如a map of China；二是在名词词尾+’s，这种形式多用于有生命的名词后，如men’s clothes(男服)。把上述两种形式结合起来，就构成了双重所有格。其构成可以是of+名词+’s，如a schoolmate of my brother’s；也可以是of+名词性物主代词，如a friend of mine。 There are two forms of English expression of nouns. One is to add “of phrases” after nouns. This form is mostly used for inanimate nouns, such as a map of China, and the second is at the end of noun +’s. After life nouns, such as men’s clothes (men’s wear). Combining the above two forms constitutes a double possession. Its composition can be of+noun+’s, such as a schoolmate of my brother’s; it can also be of + nominal pronouns such as a friend of mine.