Learn English – Ways to write “2000 year old”


Which of the following are correct and which are wrong?

  • The 2000-year-old computer
  • The 2000 year-old computer
  • The 2000 year old computer
  • The 2000-years-old computer
  • The 2000 years-old computer
  • The 2000 years old computer

In a documentary, BBC4 used the title The 2000 year-old computer, which I believe to be wrong. Am I right?

Best Answer

According to the Chicago manual of style...

When you hyphenate, it would be with hyphens between 2000 and year and old. So, 2000-year-old, but never 2000 year-old or 2000-year old. Now, to Paraphrase the CMOS for this example...

There is no need for hyphens in “2000 years old.” If you are using a phrase like that to modify another word or phrase, however, you need to bind it together with hyphens (a 2000-year-old grudge). Likewise, use a hyphen if “years old” comes before the noun it modifies (a years-old phobia over wearing the wrong earrings), but leave it open if it follows the noun (the moldy accretion on her cell phone was years old). Finally, you will need hyphens when the phrase is used as a noun (enough pizza for three 2000-year-olds).

So, taking that into account, a 2000-year-old computer would be correct. Or, if you were to rephrase, "a computer that was 2000 years old" would also be correct.

You are right. BBC4 was wrong.