1) own 无论何时前面必须有物主代词（my, your, his, our, their 等），不能放定冠词 the 或不定冠词 a / an。

2) 定指的事物，说 my own + 名词，your own + 名词，等等；不定指的事物，说 a + 名词 + of my own，a + 名词 + of your own 等等。

• a car of his own他自己的一辆车子
• He seemed to harbour political ambitions of his own.他似乎抱有自己的政治野心。
• Yet Blum had a secret policy of his own.然而勃鲁姆有自己的秘密方针。

3) 有些事物，是所有主通常必然或照例应该具有的，尽管是第一次提到，也可以认为属于定指的范围（当然，这个界限不是截然分明的）。

• I saw it with my own eyes (*with eyes of my own).是我亲眼看见的。
• I have my own bedroom (*a bedroom of my own).我有自己的寝室。
• The apartment has its own entrance (或 an entrance of its own).公寓有自己单独的出入口。
• I'd like to have my own room(或 a room of my own).我想有自己的房间。
• She makes her own clothes (*clothes of her own).她自己缝制衣服。
• Each city has its own peculiarities (或 peculiarities of its own).每个城市都有自己的特点。
• You'll have to make up your own mind (*a mind of your own).你将要自己打定主意。
• He and his wife have their own car (在私人汽车不普及的贫穷国家就说 a car of their own).他们夫妻自己有汽车。
• He has an airplane of his own (少说 his own airplane).他自己有飞机（私人飞机即使在美国也不普及）。
• The hotel has its own swimming pool (*a swimming pool of its own).旅馆有自己的游泳池（通常都有）。