appropriate

Compared meaning: suitable or correct for a situation (adjective).

比较义项：恰当的、合适的（形容词）。

• right

  Informal, everyday word for the correct or fitting choice among options; common in casual speech, especially with things like tools, times or people.

  口语化、日常用词，指在若干选项中正确或合适的那一个；在描述工具、时间、人选等时常用于随意的口语表达。

  This is the right tool for tightening these small bolts.

  这是拧这些小螺栓合适的工具。

• appropriate 本词

  More formal and neutral; used for what fits social, professional or official standards, often about behavior, clothing or language in a given setting.

  更正式、更中性，指符合社会、职业或官方标准的事物，常用于描述特定场合下的行为、着装或用语。

  The teacher reminded students to use appropriate language in class.

  老师提醒学生们在课堂上使用恰当的用语。

• proper

  Formal, slightly old-fashioned; stresses following the correct rules, procedure or etiquette, often used before nouns like procedure, way or shoes.

  较正式，语气略显传统，强调遵循正确的规则、程序或礼节，常用在 procedure、way、shoes 等名词前。

  Always follow the proper procedure when filing a complaint.

  提交投诉时务必遵循正确的程序。

Right, appropriate and proper all mean suitable or correct. Right is the most casual, for the correct or fitting choice. Appropriate is more formal, for what fits social or professional standards. Proper is also formal, stressing correct rules, procedure or etiquette.

这三个词在“恰当、合适”这个意义上很接近，但语气和使用场合有差别：right 最口语化，泛指“正确、合适的选择”；appropriate 较正式，强调符合特定场合或社会规范；proper 也较正式，强调符合规矩、礼节或标准做法。这里不比较 right 的“正确的”（事实层面）或“右边的”（方向）等其他义项，也不比较 proper 的“真正的，十足的”这一非正式用法。