just

Compared meaning: exactly, with no difference or error (adverb).

比较义项：确切地，精确地（副词）。

• exactly

  The most general and neutral of the three; used freely before numbers, times, places, and questions, and often stands alone to agree ('Exactly!').

  三者中最通用、最中性的词，可自由用在数字、时间、地点或疑问句前，也常单独用来表示赞同（“Exactly！”，意为“没错！”）。

  I don't know exactly how much it costs.

  我不知道确切的价格是多少。

• just 本词

  Limited to a handful of fixed phrases such as 'just right' or 'just what I needed'; more casual in tone; its far more common sense is 'a moment ago', not compared here.

  只用于少数固定搭配，如“just right”（恰到好处）或“just what I needed”（正是我需要的），语气更口语化；它更常见的义项是“刚刚，才”，这里不作比较。

  This soup is just right, not too hot and not too cold.

  这碗汤正好合适，不太烫也不太凉。

• precisely

  More formal and technical, common with measurements or times, and can stand alone as a more formal agreement than 'Exactly!'.

  语气更正式、更专业，常用于测量或时间等场合，也可单独使用，作为比“Exactly！”更正式的赞同用语。

  The measurements must be precisely correct, or the machine won't fit together.

  测量数据必须精确无误，否则机器就装不到一起。

Exactly, just, and precisely mean 'with complete accuracy' but differ in formality: exactly is the most general, used before numbers, times, or questions; precisely is more formal, common with measurements; just appears in phrases like 'just right' (its meaning 'a moment ago' is not compared).

这三个词在“确切地、精确地”这一意义上很接近，但正式程度和用法范围不同：exactly最通用，precisely更正式、更书面，just只用于少数固定搭配（如“just right”），语气随意，且更常表示“刚刚，才”之意。这里不比较just的“刚刚，才”这一时间义项。

Compared meaning: only, merely, nothing more than this (adverb).

比较义项：仅仅，只是（副词）。

• but

  In this sense but is formal and literary, meaning 'only' or 'merely'; it appears mostly in fixed phrases and old-fashioned writing, rarely in everyday speech.

  在这个意义上，but 十分正式、书面化，相当于“仅仅”“只是”，多见于固定搭配和老式书面语中，日常口语里很少这样用。

  He is but a child, and cannot be blamed for this.

  他不过是个孩子，不能因此责怪他。

• just 本词

  Just is the most common, neutral, everyday way to say 'only'; it is casual and fits ordinary conversation and writing of any register.

  just 是表达“仅仅”最常见、最中性的说法，语气随意，适用于任何场合的日常口语和书面语。

  I just need five more minutes to finish this email.

  我只需要再花五分钟就能写完这封邮件。

• simply

  Simply adds emphasis, presenting the limitation in a plain, direct way, and can even shade into 'completely'; here it stresses how plainly true the fact is.

  simply 带有强调意味，把这种“仅仅”表达得更加干脆、直接，有时还可以带有“完全”的语气；这里强调事实的单纯明显。

  She simply refuses to apologize, no matter what anyone says.

  不管别人说什么，她就是不肯道歉。

• only

  Only is the most basic, general, and frequent word for this meaning, used freely in both speech and writing, with flexible position in the sentence.

  only 是表达这个意义最基本、最通用、最常见的词，口语和书面语中都自由使用，在句中的位置也很灵活。

  I only wanted a small slice of cake, not the whole thing.

  我只是想要一小块蛋糕，不是整个蛋糕。

But, just, only, and simply can all mean 'only', but usage differs. But is formal and literary here, rare in speech. Just and only are the most common, natural in speech and writing. Simply is stronger and more direct. But's meaning 'however' is not compared.

这几个词在“仅仅、只是”这一意义上相近，但语气和使用场合不同：but 在此义项下非常正式、书面化，现代口语中很少见；just 和 only 最常用、最口语化，可自由用于书面语和口语；simply 语气更强调、更加直接。这里不比较 but 用作转折连词（意为“但是”）的用法。

Compared meaning: morally right or good (adjective).

比较义项：道德上正直、正确的（形容词）。

• good

  The most basic, everyday word for morally right; used for people, actions, or causes without specifying fairness or the strength of feeling involved.

  最基础、最日常的表示“道德上正确”的词，用于人、行为或事业，不特别强调公正性或情感强度。

  He grew up trying to be a good person and do the right thing.

  他从小就努力做一个好人，做正确的事。

• just 本词

  Emphasizes fairness and even-handedness, especially in decisions, laws, or the treatment of other people; common in formal or legal contexts.

  强调公正、一视同仁，尤其用于决定、法律或对待他人的方式，常见于正式或法律语境。

  The judge was known for making just decisions, even in difficult cases.

  这位法官以在疑难案件中也能做出公正的判决而闻名。

• upright

  Stresses moral integrity and honesty of character built up over time; often describes a person's reputation and sounds formal or old-fashioned.

  强调品行端正、诚实正直，通常用来形容一个人一贯的人品和名声，语气较正式、略显古雅。

  Everyone in town respected him as an upright and honest man.

  镇上的人都尊敬他，认为他是一个正直诚实的人。

• righteous

  Carries the strongest moral force, often linked to religious belief or deeply held conviction; can also describe self-righteous anger or indignation.

  道德色彩最强，常与宗教信仰或坚定的道德信念相关，也可指“义愤”，有时带有自以为是的意味。

  He felt righteous anger when he saw the innocent man being punished.

  看到无辜的人受到惩罚，他感到义愤填膺。

All four can mean 'morally right'. Good is the most basic, everyday word. Just stresses fairness. Upright stresses honest character built over time. Righteous is strongest, common in religious or moral-anger contexts, sometimes self-righteous. Good's other sense and just as 'only' are not compared here.

这四个词都可表示“道德上正确、正直”，但语气和使用场合不同：good最基础、最口语化；just强调“公正、公平”；upright强调“品行端正、廉洁”；righteous语气最强，常见于宗教或道德义愤语境，有时含自以为是的意味。这里不比较good的其他常见义项（如“好的、优质的”），也不比较just作副词时“刚刚，仅仅”的用法。