1
duplicate sth
直接跟宾语，表示复制某物。
Please don't duplicate the document without permission.
未经允许请勿复印文件。
复制
先理解核心含义，再看它在真实句子里的用法。
复制
To make a copy of something.
Please don't duplicate the document without permission.
未经允许请勿复印文件。
复制
To make a copy of.
重复做；再做
To do repeatedly; to do again.
产生与...相等的事物
To produce something equal to.
再次制作或执行
make or do or perform again
duplicate
Base
原形
duplicates
3rd person
第三人称单数
duplicating
-ing
现在分词
duplicated
Past
过去式
duplicated
Past participle
过去分词
He duplicates the file every week.
他每周都会复制这个文件。
She duplicated the key yesterday.
她昨天复制了钥匙。
They have duplicated the experiment twice.
他们已经重复进行了两次实验。
规则动词
Please duplicate the document and keep one copy for yourself.
请复印这份文件，并自己保留一份副本。
The artist duplicated the painting to sell prints.
艺术家复制了这幅画以出售印刷品。
We duplicated our success by following the same strategy.
我们沿用同样的策略，再次取得了成功。
直接跟宾语，表示复制某物。
Please don't duplicate the document without permission.
未经允许请勿复印文件。
表示从某处复制到别处。
You can duplicate the data from the original file.
你可以从原始文件复制数据。
表示使用工具或方法复制。
He duplicated the key with a special machine.
他用一台特殊机器复制了钥匙。
Not this
Please duplicate the file again.
Use this
Please duplicate the file.
“duplicate”本身已包含“再次”的意思，再用“again”造成语义重复。
Not this
She duplicated the document from the original.
Use this
She duplicated the original document.
动词“duplicate”直接接宾语表示复制对象，无需使用介词“from”。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
复制文件
Make sure you duplicate the file before editing it.
编辑前务必复制一份该文件。
重复劳动
Please check the report first so we don't duplicate work.
请先看一下报告，免得我们重复劳动。
重复出相同的结果
Other labs have struggled to duplicate the results.
其他实验室一直难以重复出这些结果。
重复实验
The team duplicated the experiment to confirm the findings.
团队重复了实验，以确认这些发现。
配钥匙；复制钥匙
I had to duplicate the front-door key.
我不得不配一把前门钥匙。
Use duplicate naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
联想：du- 像 double（翻倍），把文件翻倍复制成两份，就是 duplicate（复制、重复做）。
语域：formal 常见场景：文件与档案管理、实验与研究、办公事务 作为动词，duplicate 比较正式，多用于书面或正式场合；日常口语中表达“复制”更常用 copy，表达“重复做”更常用 repeat 或 do again。
及物动词，后接名词或代词。
Dictionary facts from ECDICT, WIKTIONARY.