Is next door one word or two?

The spelling of "next door" depends on its grammatical function. It is two words when used as an adverb, and typically two words joined by a hyphen when used as an adjective. It is generally not written as a single, unhyphenated word.

Understanding the Usage

The phrase "next door" can function in two primary ways in English:

As an Adverb

When "next door" describes where an action takes place or indicates location, it functions as an adverb. In this case, it is spelled as two separate words.

• Function: Modifies a verb, adjective, or another adverb, indicating proximity.
• Spelling: next door (two words)
• Examples:
  • "I went next door to the bathroom." (Describes where you went)
  • "They live next door." (Indicates where they live)
  • "The shop is just next door." (Describes the shop's location)

As an Adjective

When "next-door" describes a noun, it functions as an adjective. In this case, it is typically spelled as a hyphenated compound adjective.

• Function: Modifies a noun, describing something that is adjacent.
• Spelling: next-door (hyphenated)
• Examples:
  • "Our next-door neighbor is very friendly." (Describes the neighbor)
  • "She moved into the next-door apartment." (Describes the apartment)
  • "They held a party in the next-door garden." (Describes the garden)

Summary Table

To clarify the correct usage, refer to the table below:

Practical Insights

• When to hyphenate: Hyphenate "next-door" when it comes before the noun it modifies (e.g., "the next-door house").
• When not to hyphenate: Do not hyphenate "next door" when it comes after the verb or when it functions adverbially (e.g., "He lives next door").
• Consistency: While language evolves, adhering to these standard spellings ensures clarity and professional communication.

Understanding the difference between the adverbial and adjectival forms of "next door" helps in accurate and effective writing.