正如名詞后綴-er 一樣，-or 也是最重要的表示行為者的名詞后綴。不過，-or 是來源于拉丁語的非能產(chǎn)型的后綴。它只與拉丁語源的動詞或動詞詞根相結(jié)合，構(gòu)成名詞，其意思為a person or thing that ～s（...者，...物）。由于受拉丁構(gòu)詞的影響，有時-or 前還帶有其他拉丁詞尾成份，常見的形態(tài)有-ator,-itor等，可將它們看作-or 的異體。

后綴-or 表示“人”。

1.actor [act v.表演；-or →]
n.演員
舉例：The boy dreamed of becoming an actor. 那男孩子一心想當演員。

2.doctor [doct = to teach 教；-or →“教育者”→]
n.學者，先生；醫(yī)生
舉例：A doctor must have a license to practise medicine. 醫(yī)生要有執(zhí)照才能行醫(yī)。

3.testator
n.man who has made a testament立遺囑的人 test=witness
The wording of his will makes it very clear that it was the intention of the testator to leave his entire estate to his daughter.
遺囑中的字句清楚地表明，立遺囑的人要把全部財產(chǎn)都留給他的女兒。


后綴-or 表示“物”。

1.tractor 拖拉機，螺旋槳飛機
The tractor took up the slack and pulled the trailer out of the mud.
拖拉機拉緊拖纜把拖車從泥中拉了出來。

2.detector n. 探測器
A device for converting energy form one form to another. In relation to computers, the term is applied to a read/write head, to detector of sector marks in a magnetic disc system, and to electronic/sonic
pulse converters of delay line memory.

把能量從一種形式轉(zhuǎn)換成另一種形式的裝置。在與計算機有關(guān)時，這個術(shù)語用在磁盤系統(tǒng)中的讀／寫磁頭、扇面標記的檢測上，以及用在延遲線存儲器的電子或聲波脈沖變換器上。

3.refrigerator
n.冷藏庫，冰箱
舉例：Milk,meat and fish must be stored in a refrigerator to prevent spoiling. 牛奶、魚，肉等應存放在冰箱里保鮮。