Is Costed a Word? What is the Past Tense of Cost?

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Candace Osmond

Candace Osmond studied Advanced Writing & Editing Essentials at MHC. She’s been an International and USA TODAY Bestselling Author for over a decade. And she’s worked as an Editor for several mid-sized publications. Candace has a keen eye for content editing and a high degree of expertise in Fiction.

Some verbs stay the same in their simple past and past participle form, and they’re called irregular verbs. But is cost one of them? What is the past tense of cost?

Both cost and costed are correct. But they might have different uses. Find out the difference between cost and costed and how to use them in a sentence.

Cost or costed is the past tense form of the verb cost. However, American and British English prefer cost as the simple past tense. The verb means the amount needed to buy, do, or pay for something.

Why is Costed Wrong?

Costed Ngram
Costed usage trend.

Costed is not entirely wrong. In fact, Canadians and other varieties of English-speaking countries outside North America use it. 

American English considers cost as an irregular verb. Its simple past and past participle form do not use -ed or -d at the end. Instead, it remains uninflected in the past tense. 

For example, Americans would say that milk cost less yesterday. But Canadians might say, “milk costed less yesterday.”. 

There’s also a rule that cost as a linking verb does not change in spelling in the past tense. Linking verbs are verbs that only connect the subject and predicate. For example, it costs me five dollars. 

However, use the regular past form if you use it as an action verb which means to figure out how much something will cost you. For example, I haven’t costed the business proposal yet.

Cost can also be a noun that means the amount of money you need to purchase, do, or pay for something.

How Do You Use Cost in a Sentence?

  • The capital cost is twice as much as last year.

How Do You Use Costed in a Sentence?

American news publications prefer cost, but there are instances where they use costed.

The menu is fully costed, reasonably priced and, importantly, returns a healthy profit. [Herald Scotland]

The plan isn’t fully costed and would require hundreds of millions in new revenues. []

But Mr Abbott said the policy would be fully costed. [Sydney Morning Herald]

[T]he Military Veterans Bill, passed by Parliament last year, broke legislative rules because it could not be costed. [Independent Online]

How Do You Use Costly in a Sentence?

The ‘Anticipation Error’ Is Turning Decisions Into Costly Disasters. There’s an Easy Way to Avoid It (Inc.)

The Max 10, an extended version of the company’s flagship single-aisle jet that was grounded in 2019 after two fatal crashes, must be approved by the Federal Aviation Administration by December or it could face a costly redesign. (Bloomberg)

Amtrak’s expansion to the Hinterlands will be costly to the government & the economy. (Forbes)

Assisted living communities average more than $4,000 monthly. This is where they are the most and least costly. (CNBC)

So, Both are Correct

Use the simple past tense of cost in American and British English. And use costed if you are writing or speaking to a Canadian audience. You can also use cost if you’re referring to the linking verb and costed for the action verb.

The difference between them is easy to memorize. Keep practicing by using the verb in a sentence whenever you get the chance! Learn about more differences in American and Canadian/IK spellings like analog vs. analogue or fueled and fuelled to improve your writing skills.