指代不同:
1、their:是形容词物主代词。
2、theirs:是名词性物主代词。
用法不同:
1、their是复数第三人称的所有格形式,是复数形容词性物主代词,在句中只可用作定语,其后常接复数名词。有时为了避免显示性别,their还可代替his,her用作anybody。
2、theirs为复数第三人称的名词性物主代词,可单独使用,起名词作用,在句中可作主语、宾语或表语,但不可用作定语,无复数形式。有时theirs还可与of连用构成双重所有格。
theirs:
1、And when the experimenter stuck his tongue out, infants stuck theirs out.
实验者吐舌头的时候,婴儿才吐舌头。
2、But the quality of theirs compares much lower with ours.
但他们的质量不能和我们的产品相比。
3、They have to pay a call on an old friend of theirs tonight
他们今晚得去看望一个老朋友。
their:
The Government are back-pedalling on their election promises.
内阁正在背弃它竞选时的诺言。
The ring was important to her as an emblem of their love.
这枚戒指是他们爱情的象征,对她是重要的。