英语语法解析：复合形容词中“-long”后缀的正确用法与数字书写规范

When learning English, the formation of compound adjectives can present a subtle yet significant challenge. A common point of confusion arises with phrases like "a fifty-kilometre-long road" versus "a fifty-kilometre road." Is the "-long" suffix necessary, or is it redundant? This article distills insights from a detailed language forum discussion to provide clear, professional guidance on the usage, hyphenation, and numeral conventions for these descriptive phrases.

在学习英语时，复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。的构成可能会带来微妙但重要的挑战。一个常见的困惑点出现在诸如 "a fifty-kilometre-long road" 与 "a fifty-kilometre road" 这样的短语中。后缀 "-long" 是必要的，还是冗余的？本文提炼了一个详细语言论坛讨论的见解，为这些描述性短语的用法、连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。使用和数字规范提供清晰、专业的指导。

To Use "-Long" or Not? That is the Question

The core of the inquiry revolves around whether the inclusion of "-long" in compound adjectives denoting length or duration is mandatory, optional, or incorrect. The consensus from native speakers and language experts is clear: its inclusion is generally optional but context-dependent.

这个问题的核心在于，在表示长度或持续时间的复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。中，加入"-long"是强制性的、可选的，还是错误的。来自母语者和语言专家的共识很明确：它的加入通常是可选的，但取决于上下文。

The General Rule: Optional Clarity

In everyday language, it is perfectly common and acceptable to omit "-long." The unit of measurement itself often implies the dimension being described.

在日常语言中，省略"-long"是非常普遍且可接受的。度量单位本身通常暗示了所描述的维度。

A fifty-kilometre road is understood to be fifty kilometres in length.
- 一条五十公里长的道路（被理解为长度为五十公里）。
A ninety-minute film is understood to have a runtime of ninety minutes.
- 一部九十分钟长的电影（被理解为时长为九十分钟）。

Adding "-long" (a fifty-kilometre-long road) can sometimes sound more natural or provide emphasis, but it is not grammatically required for comprehension. It explicitly states the attribute, removing any potential, albeit unlikely, ambiguity (e.g., a road that costs fifty kilometres to build?).

加上"-long"（一条五十公里长的道路）有时听起来更自然或起到强调作用，但从语法上讲，它并非理解所必需的。它明确地陈述了属性，消除了任何潜在的（尽管不太可能的）歧义（例如，一条造价为"五十公里"的道路？）。

When "-Long" Becomes Essential or Preferred

There are contexts where "-long" is either obligatory or strongly preferred:

在某些语境中，"-long"是强制性的或强烈推荐的：

With Less Specific Time Periods: For durations like "week," "month," or "year," where the unit alone could be misinterpreted (e.g., "a week series" is unclear), "-long" is typically necessary.
- Essential: "A week-long festival." (一个为期一周的节日。)
- Unclear/Incorrect: "A week festival."
For Formal or Exam Settings: When in doubt, especially in academic or examination contexts where stylistic precision is evaluated, including the "-long" suffix is the safer choice. It demonstrates a precise application of the compound adjective rule and avoids any risk of being marked incorrect for omission.
- Safer for exams: "The engineers surveyed the fifty-kilometre-long pipeline." (工程师们勘测了那条五十公里长的管道。)
- Common in speech/writing: "The engineers surveyed the fifty-kilometre pipeline."

与不太具体的时间段连用： 对于像 "week"、"month" 或 "year" 这样的持续时间，仅使用单位可能会被误解（例如，"a week series" 含义不清），"-long" 通常是必要的。

必需： "一个为期一周的节日。"

不清晰/错误： "A week festival."

在正式或考试场合： 如有疑问，特别是在评估文体精确性的学术或考试环境中，包含 "-long" 后缀是更安全的选择。 它展示了对复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。规则的精确应用，并避免了因省略而被判错的风险。

对考试更安全： "工程师们勘测了那条五十公里长的管道。"

在口语/写作中常见： "工程师们勘测了那条五十公里长的管道。"

Hyphenation: Connecting the Elements Correctly

A critical aspect of forming grammatically correct compound adjectives is proper hyphenation. The rule is to hyphenate all the elements when they collectively modify a noun that follows.

构成语法正确的复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。的一个关键方面是正确使用连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。。规则是：当所有元素共同修饰后面的名词时，将它们全部用连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。连接起来。

Correct: a fifty-kilometre-long road; a ninety-minute-long film; a two-year-old cat.
Incorrect: a fifty kilometre-long road; a ninety minute long film.

The hyphens link "fifty," "kilometre," and "long" into a single conceptual unit that describes "road." This prevents misreading. For example, "a two year old cat" without hyphens could initially be parsed as "a two year, old cat," which is nonsensical.

连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。将 "fifty"、"kilometre" 和 "long" 连接成一个描述 "road" 的单一概念单元。这可以防止误读。例如，没有连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。的 "a two year old cat" 最初可能被解析为 "a two year, old cat"，这是没有意义的。

正确： 一条五十公里长的道路；一部九十分钟长的电影；一只两岁大的猫。

错误： a fifty kilometre-long road; a ninety minute long film.

Numbers: Figures vs. Words

The final common question is whether to use numerals (50) or words (fifty). This falls under style guide conventions, which can vary.

最后一个常见问题是使用数字（50）还是单词（fifty）。这属于文体指南的规范，可能有所不同。

Common Style Guide Principles

While publications have specific rules, some general principles are widely accepted:

尽管出版物有具体规则，但一些通用原则被广泛接受：

The One-to-Nine / Ten-and-Above Rule: A common baseline is to spell out numbers from one to nine and use numerals for 10 and above.
- "They built three bridges." (他们建造了三座桥。)
- "They built 15 bridges." (他们建造了15座桥。)
Beginning of a Sentence: Always spell out a number that begins a sentence.
- "Fifty participants attended." Not "50 participants attended." (五十名参与者出席了。)
Technical vs. Literary Context: Technical, scientific, and business writing heavily favor numerals for clarity and efficiency (e.g., "a 50 km road," "a 90-minute film"). Literary writing may spell out numbers more frequently.
Compound Adjectives: When a number is part of a hyphenated compound adjective, consistency with the chosen style is key. Both "a 50-kilometre-long road" and "a fifty-kilometre-long road" are correct, adhering to different style preferences.

一到九 / 十及以上规则： 一个常见的基线是拼写出一到九的数字，对十及以上的数字使用数字。

"他们建造了三座桥。"

"他们建造了15座桥。"

句首： 总是拼写出句首的数字。

"五十名参与者出席了。" 而非 "50 participants attended."

技术性与文学性语境： 技术、科学和商业写作为了清晰和高效，强烈倾向于使用数字（例如，"一条50公里长的道路"，"一部90分钟的电影"）。文学写作可能更频繁地拼写数字。

建议： 对于考试，遵循题目或课程材料中使用的惯例。如果规则不明确，拼写出一到九的数字，对更大的数字使用数字，这是一个稳妥的策略。

Recommendation: For exams, follow the convention used in the test or course materials. If the rule is unclear, spelling out numbers one to nine and using figures for larger numbers is a safe strategy.

建议： 对于考试，遵循题目或课程材料中使用的惯例。如果规则不明确，拼写出一到九的数字，对更大的数字使用数字，这是一个稳妥的策略。

Conclusion: Precision in Practice

Mastering compound adjectives like "fifty-kilometre-long" involves understanding a blend of grammatical rules and stylistic conventions. Remember:

The "-long" suffix is optional for common units like kilometres and minutes but is safer to include in formal writing and exams.
Hyphenate all elements of the compound adjective before a noun.
Choose between numerals and words based on context, adhering to common style rules when in doubt.

By applying these guidelines, you can navigate these descriptive constructions with confidence and precision, ensuring your English is both grammatically sound and stylistically appropriate.

掌握像 "fifty-kilometre-long" 这样的复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。需要理解语法规则和文体惯例的结合。请记住：

对于公里和分钟等常见单位，"-long" 后缀是可选的，但在正式写作和考试中包含它更安全。

在名词前，将复合形容词由两个或多个词组成的形容词，通常用连字符连接，用于修饰名词，如“fifty-kilometre-long”。的所有元素用连字符标点符号“-”，用于连接复合形容词的组成部分，确保语法正确和意义清晰。连接起来。

根据语境在数字和单词之间做出选择，如有疑问，遵循常见的文体规则。

通过应用这些准则，您可以自信而精确地使用这些描述性结构，确保您的英语既语法正确又文体得当。