ascertain

Compared meaning: to find out a fact or truth (verb).

比较义项：查明，得知某事的真相或事实（动词）。

• determine

  Used when a process, test, or result establishes a fact; the subject is often impersonal (a result, an experiment) rather than a person investigating; more neutral in register than ascertain.

  常用于某个过程、测试或结果查明事实，主体常是非人称的（如结果、实验），而不是人在调查；语域比ascertain更中性。

  The results will determine who wins the competition.

  比赛结果将查明谁赢得比赛。

• learn

  Means to find out passively, often by being told or through experience, without deliberate investigation; common with people, especially children, and everyday facts; more casual than determine or ascertain.

  指被动地得知某事，往往是被告知或通过经历得知，而非经过刻意调查；常用于人，尤其是儿童，以及日常事实；语气比determine和ascertain更随意。

  Children learn new words quickly when they read every day.

  孩子们每天阅读时能很快得知新单词的意思。

• ascertain 本词

  Formal, often used in official, investigative, or written contexts; emphasizes making certain of a fact through deliberate effort or verification; stronger and more precise than learn.

  语气正式，常用于官方、调查或书面语境；强调通过刻意努力或核实来确认某一事实；比learn更强调准确性和确定性。

  The detective needed more time to ascertain who was responsible.

  侦探需要更多时间来查明是谁负责此事。

Determine, learn and ascertain all mean to find out a fact. Determine is used when a process or result establishes a fact. Learn means finding out passively, often by being told, common with people. Ascertain is formal, stressing deliberate investigation to make certain.

这三个词在“查明、得知事实”这一意义上相近，但determine偏重通过过程或结果得出结论，主体常是非人称的（如结果、测试），语域中性；learn较随意，常指被动得知，尤其用于人，尤其是儿童；ascertain最为正式，强调通过调查、核实以确定无疑。这里不比较determine的“决定，下定决心”义，也不比较learn的“学习（技能、语言等）”义。