1
ascertain that clause
that从句通常陈述已确认的事实。
The doctor ascertained that the patient had recovered.
医生查明病人已经康复。
查明，弄清，确定
先理解核心含义，再看它在真实句子里的用法。
查明，弄清，确定
find out or learn with certainty
The doctor ascertained that the patient had recovered.
医生查明病人已经康复。
常用于正式或书面语境
确定；发现或建立。
To find out definitely; to discover or establish.
ascertain
Base
原形
ascertains
3rd person
第三人称单数
ascertaining
-ing
现在分词
ascertained
Past
过去式
ascertained
Past participle
过去分词
I ascertain the facts.
我查明事实。
He ascertained the truth.
他查明了真相。
They have ascertained the cause.
他们已经确定了原因。
The detective tried to ascertain the truth from the witness.
侦探试图从目击者那里查明真相。
After reviewing the data, the scientists ascertained the cause of the error.
在审查数据后，科学家们确定了错误的原因。
The committee is currently ascertaining the financial impact of the proposal.
委员会目前正在查明该提案的财务影响。
that从句通常陈述已确认的事实。
The doctor ascertained that the patient had recovered.
医生查明病人已经康复。
wh-从句如whether, how, what等。
We need to ascertain whether the report is accurate.
我们需要查明报告是否准确。
名词短语常为事实、真相、原因等抽象概念。
Investigators tried to ascertain the cause of the fire.
调查人员试图确定火灾的原因。
Not this
He ascertained his innocence in court.
Use this
He asserted his innocence in court.
学习者混淆了'ascertain'（查明）和'assert'（声称）。'Ascertain'表示通过调查确定事实，而'assert'表示自信地声明。在表达声明主张时应用'assert'。
Not this
The detective needs to ascertain about the cause of the fire.
Use this
The detective needs to ascertain the cause of the fire.
'Ascertain'是及物动词，直接跟宾语，不需要介词'about'。错误地添加介词是受到中文表达'查明关于'的影响。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
查明事实
We need to ascertain the facts before making a decision.
在做出决定之前，我们需要查明事实。
查明真相
Detectives worked tirelessly to ascertain the truth.
侦探们不遗余力地查明真相。
查明是否
The doctor ran tests to ascertain whether the patient had been infected.
医生进行检查以确定病人是否被感染。
查明原因
An investigation was launched to ascertain the cause of the fire.
已展开调查以查明火灾原因。
确认身份
Police used DNA analysis to ascertain the identity of the victim.
警方使用DNA分析来确认受害者的身份。
Use ascertain naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
as certain 的合音，意为确定、查明。
通常用于正式语境，如法律、调查、学术研究等，表示通过努力查明事实或真相。
Words ending in -tain pronounced /teɪn/ (contain, obtain, retain, detain, entertain) rhyme with ascertain. Note: 'certain' shares spelling but is pronounced /ˈsɜːrtən/ (no /eɪ/ sound).
Dictionary facts from ECDICT, WIKTIONARY, WORDNET.