Runaway vs. Run away – Which is Correct?

The key difference between runaway and run away lies in their grammatical function. Runaway is typically an adjective or a noun, describing something that has run away or a person who has done so. Run away is a phrasal verb, meaning to escape or flee. Both are correct in American English, but they serve distinct roles in a sentence.

Runaway or Run Away – Which is Correct?

Both “runaway” and “run away” are correct in American English, but they are used in different contexts due to their distinct grammatical roles. Understanding these roles is crucial for proper usage. “Runaway” is a single word that functions as either an adjective or a noun, while “run away” is a two-word phrasal verb.

The Best Trick to Remember the Difference

To remember the difference, use the “part of speech” trick. If you can replace the word with a single adjective (like “uncontrolled” or “escaped”) or a single noun (like “fugitive” or “escapee”), then “runaway” (one word) is likely correct. If you need a verb phrase to describe the action of fleeing or escaping, then “run away” (two words) is appropriate.

Word	Part of Speech	Meaning	Example
runaway	Adjective or Noun	Adjective: out of control, escaped; Noun: a person or animal that has run away.	The runaway train sped down the tracks. (Adjective) The police searched for the runaway. (Noun)
run away	Phrasal Verb	To escape, flee, or leave a place or situation.	He decided to run away from home.

How to Use Runaway

The single word “runaway” primarily functions as an adjective or a noun. As an adjective, it describes something that is out of control, has escaped, or is rapidly increasing. As a noun, it refers to a person or animal who has fled, or an event that is out of control. It often carries a sense of urgency or lack of constraint.

Example 1: The company experienced runaway success after launching its new product line, exceeding all expectations.

Example 2: Authorities issued a warning about a runaway inflation rate that was rapidly eroding purchasing power.

Example 3: The shelter was trying to locate the owner of the runaway dog found wandering in the park.

What are the different forms of runaway?

As an adjective, “runaway” does not typically have comparative or superlative forms in the traditional sense (e.g., “more runaway”). It’s usually used as an absolute descriptor. As a noun, its plural form is “runaways.”

Etymology of the word runaway

The word “runaway” emerged in the 16th century, formed by combining the verb “run” and the adverb “away.” It initially functioned as a noun referring to someone who had fled. Its adjectival use, describing something that has escaped or is out of control, developed later, by the 18th century.

How to Use Run Away

“Run away” is a phrasal verb meaning to escape, flee, or leave a place or situation, often secretly or without permission. It emphasizes the action of departing from something. The verb “run” can be conjugated according to tense, while “away” remains constant. It can be used in both formal and informal contexts depending on the situation.

Example 1: Faced with overwhelming debt, they felt the urge to run away and start fresh somewhere new.

Example 2: The children promised not to run away from their parents while at the busy amusement park.

Example 3: She decided to run away from the oppressive situation, seeking freedom and independence.

What are the different forms of run away?

As a phrasal verb, “run away” conjugates the verb “run” according to tense and subject.

For a deeper dive into conjugating the base verb, explore the distinctions between Ran vs. Run.

• Present Tense: I run away, you run away, he/she/it runs away, we run away, they run away
• Past Tense: ran away (e.g., “He ran away from the noise.”)
• Present Participle: running away (e.g., “They are running away from their problems.”)
• Past Participle: run away (e.g., “She had run away before.”)

Etymology of the word run away

The phrasal verb “run away” combines the Old English verb “runnan” (to move swiftly) with the Old English adverb “aweg” (from a place). The concept of “running” to “move from” a location has been present in English for centuries, with the specific phrasal verb “run away” solidifying its meaning of fleeing or escaping by the late Middle Ages.

Related Concepts

Understanding broader grammatical concepts helps clarify the distinction between “runaway” and “run away.”

• Phrasal Verbs: These are combinations of a verb and an adverb or preposition (or both) that create a new meaning distinct from the individual words. “Run away” is a classic example, where “run” (move quickly) combines with “away” (direction) to mean “flee.”
• Compound Adjectives: Sometimes, two words combine to form a single adjective that modifies a noun. “Runaway” functions this way when it describes a noun (e.g., “runaway success”). It’s often written as one word when it precedes the noun it modifies.
• Open vs. Closed Compounds: “Run away” is an open compound (two separate words), while “runaway” is a closed compound (one word). The choice often depends on grammatical function (verb vs. adjective/noun).

Examples from Media and Literature

• In the classic novel The Adventures of Huckleberry Finn, Huck Finn famously decides to run away from his abusive father and the constraints of society.
• The film Runaway Bride, starring Julia Roberts, depicts a character who repeatedly leaves her fiancés at the altar, earning her the title of a runaway.
• News headlines often report on a “runaway train” or a “runaway truck” when a vehicle loses control.
• The children’s book The Runaway Bunny tells the story of a young bunny who imagines various ways to run away and his mother’s loving responses.
• Economists frequently discuss the potential for a “runaway deficit” if government spending continues unchecked.

Practice Exercises

Choose the correct word to complete the sentence.

1. The police were looking for a _________ who had escaped from the juvenile detention center.
2. She felt an overwhelming desire to _________ from all her responsibilities.
3. The _________ inflation was causing significant economic instability.
4. Did you hear about the dog that managed to _________ from its yard?
5. The movie depicted a thrilling chase scene involving a _________ horse-drawn carriage.

Answer Key

1. runaway
2. run away
3. runaway
4. run away
5. runaway

Runaway Synonyms

Synonym	Definition
Escaped (adj.)	Having broken free from confinement or control.
Fugitive (n.)	A person who has escaped from captivity or is in hiding.
Uncontrolled (adj.)	Not restrained or managed; wild.
Rampant (adj.)	(Especially of something unwelcome or unpleasant) flourishing or spreading unchecked.
Defector (n.)	A person who abandons their country or cause in favor of an opposing one.

Run Away Synonyms

Synonym	Definition
Flee	To run away from a place or situation of danger.
Escape	To break free from confinement or control.
Abscond	To leave hurriedly and secretly, typically to avoid detection or arrest.
Bolt	To run away suddenly.
Decamp	To leave a place suddenly and secretly.

Frequently Asked Questions

Question 1: Can “runaway” ever be used as a verb?
No, “runaway” is strictly an adjective or a noun. The verb form is always “run away” (two words).

Question 2: Is “runaway” only used in negative contexts?
While often associated with negative situations like runaway trains or children, “runaway” can also describe positive, uncontrolled growth, such as “runaway success” or “runaway popularity.”

Question 3: How do I know if I need a phrasal verb or an adjective?
If you are describing an action or a state of fleeing, use the phrasal verb “run away.” If you are describing a noun that is out of control or has escaped, or using it as the noun itself, use the adjective or noun “runaway.”

Conclusion

Distinguishing between “runaway” and “run away” is straightforward once you grasp their fundamental grammatical roles. “Runaway” (one word) serves as an adjective, describing something out of control or having escaped, or as a noun for the entity that has fled. “Run away” (two words) is a phrasal verb, indicating the action of fleeing or escaping. Mastering this distinction enhances clarity and precision in your writing.

Pro Tip: When in doubt, consider if you’re describing a characteristic (adjective/noun) or an action (verb). Using the correct form not only improves readability but also upholds your professional reputation as a skilled communicator.