1. Introduction to Hyphens

Hyphens are punctuation marks used to connect words and clarify meaning. One of their primary functions is to form compound adjectives, which can enhance sentence clarity and precision.

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2. What are Compound Adjectives?

A compound adjective is formed when two or more words are combined to modify a noun. Hyphens are used to link these words when they appear before the noun they modify.

Example:

• “She is a well-known author.”
• “They live in a five-bedroom house.”

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3. When to Use Hyphens in Compound Adjectives

a. Before Nouns

Use hyphens when the compound adjective appears before the noun it modifies.

Examples:

• “The high-speed train arrived on time.”
• “He is a full-time employee.”

b. Age and Numbers

Hyphens are also used in compound adjectives that describe age or numbers.

Examples:

• “They have a two-year-old child.”
• “I bought a 10-inch cake.”

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4. Exceptions and Special Cases

a. After Nouns

Do not use hyphens when the compound adjective follows the noun it modifies.

Examples:

• “The author is well known.”
• “The train is high speed.”

b. Adverb + Adjective Combinations

Do not hyphenate compound adjectives formed with adverbs that end in -ly.

Example:

• “She is a beautifully crafted piece of art.”
• “He is an extremely talented musician.”

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5. Common Mistakes to Avoid

• Incorrect Hyphenation: Avoid unnecessary hyphenation. Not all two-word phrases need hyphens.
• Incorrect: “The blue sky is beautiful.”
• Correct: “The bright-blue sky is beautiful.”
• Confusing Compound Nouns with Adjectives: Ensure that the hyphen is used for adjectives only.
• Incorrect: “I need to buy a coffee table.”
• Correct: “I need to buy a large coffee-table book.”