Years old or Year-old?

Years old or Year-old:  Meaning, Examples & Difference

In English, there are two common ways to describe age: years old and year-old. Although both expressions indicate age, they are used in different contexts. This article will explore the difference between them, along with rules and examples to illustrate their correct usage.

When talking about the age of a person or object in English, we use two constructions: years old and year-old. While both express age, they follow distinct grammatical rules that affect sentence structure and meaning. Let’s dive into how and when to use each of them.

Years old

The phrase years old is used at the end of a sentence to indicate age. It’s the standard expression when simply stating how old someone or something is. The structure is: subject + is/are + # years old. Here are a few examples:

• My grandfather is seventy-five years old.
• This bridge is 150 years old.
• Her son is just two years old.

Year-old

Year-old functions as an adjective when you want to specify age directly before a noun, providing a more descriptive label. In this case, the phrase always includes a hyphen and helps make the sentence concise. The structure is: #-year-old + noun. Examples include:

• They have a ten-year-old dog.
• We visited a 500-year-old castle.
• The school hired a thirty-year-old teacher.

These two forms are not interchangeable. Years old is used to complete a thought about age, whereas year-old creates a precise description before a noun. In this article, we’ll explore the rules and nuances of each form, helping you easily distinguish between them and avoid common mistakes.

Years old: Meaning, Grammar, Usage & Examples

Years old is a phrase used to describe the age of a person or object. It is typically placed at the end of a sentence to indicate a specific age. This phrase is neutral and used to simply state someone’s or something’s age without additional emphasis.

Meaning

Years old literally means “# years,” referring to the number of years someone or something has existed. It can be used for both people and objects. For example:

• She is twenty years old.
• This building is over a hundred years old.

Grammar

When using years old, there are a few important rules to follow:

• Use of numbers: A numeral always accompanies years old to indicate a specific age (e.g., 5 years old – 5 years, 30 years old – 30 years).
• Form of “years”: When the age exceeds one year, the word years is always plural (e.g., 3 years old – 3 years). The only exception is when talking about one year, where 1 year old is used.
• Position in a sentence: The phrase years old is always placed at the end of the sentence or phrase that describes the age. For example:
  • Our cat is ten years old.
  • The computer I bought is two years old.

Usage

Years old is mostly used to directly inform someone of the age of a person, animal, or object. It’s a natural way of describing age in everyday English. This expression is useful when age is added as extra information or at the end of a sentence.

Examples

• My daughter is eight years old.
• That tree is fifty years old.
• Their house is 120 years old.
• He is just one year old.
• These cars are five years old.

Tips for Usage

• Always remember to use the plural form years when the age is more than one year.
• Use years old only at the end of the sentence or when the age is not part of an adjective describing the noun. For example, Her dog is three years old, but a three-year-old dog.

Common Mistakes

• Forgetting the plural form of “years”: In English, it’s essential to use the plural or singular form depending on the number of years.
  • Incorrect: She is five year old.
  • Correct: She is five years old.
• Incorrect sentence structure: Years old should not be placed before a noun.
  • Incorrect: a 10 years old boy
  • Correct: a 10-year-old boy or He is 10 years old.

Year-old: Meaning, Grammar, Usage & Examples

Year-old is an adjective phrase used to describe the age of a person, animal, or object. Unlike years old, it is placed before a noun and is used for a more specific and clear description. This expression is always hyphenated and allows you to succinctly specify age as part of the description.

Meaning

Year-old is used to describe age as a characteristic that defines a person, animal, or thing. It is an adjective combined with a noun, creating more compact and structured descriptions. For example:

• a five-year-old girl
• a fifty-year-old tree

Grammar

When using year-old, there are a few important rules to follow:

• Hyphen: The expression year-old is always hyphenated. This rule helps to treat it as a single adjective word before the noun, and it should not be separated. For example:
  • a ten-year-old car
• Singular form of “year”: Regardless of the age, the word year is always used in the singular form along with -old. For example:
  • a twenty-year-old person
  • a three-year-old puppy
• Word order: Year-old is always placed before the noun it describes. This structure helps create concise descriptions, especially in both spoken and written English. For example:
  • an eight-year-old student

Usage

Year-old is used when you need to convey age as a defining characteristic of the subject. It’s useful in contexts where age is an important part of the description, providing essential information about the object or person. For example:

• a hundred-year-old building
• a six-year-old child

Examples

• She has a two-year-old daughter.
• They live in a 300-year-old castle.
• I recently bought a four-year-old car.
• He is a seventeen-year-old athlete.
• This book is about a fifteen-year-old hero.

Tips for Usage

• Be sure to use a hyphen in the year-old expression when placed before a noun.
• Don’t add an s to year—it always stays singular, regardless of the number of years.
• Use year-old only when describing something before a noun, to indicate age as part of its characteristic.

Common Mistakes

• Missing hyphen: Avoid omitting the hyphen, as year-old functions as an adjective and must always be written with a hyphen before a noun.
  • Incorrect: a 10 year old car
  • Correct: a 10-year-old car
• Using “years” instead of “year”: In the year-old expression, year always remains singular, even when referring to more than one year.
  • Incorrect: a five-years-old boy
  • Correct: a five-year-old boy

Key Differences Between “Years Old” and “Year-old”

Additional Examples for Comparison

Years Old

• My son is five years old.
• This tree is 100 years old.
• They bought a 20-year-old house, and now it’s 50 years old.
• She is only six years old, but she reads very well.

Year-old

• a five-year-old child
• a 100-year-old tree
• a 20-year-old house
• an eight-year-old car

This table helps clarify when and how to use “years old” or “year-old” for expressing age correctly.