“Cost” can be either a noun or a verb.
As a noun, “cost” can refer to the money needed to buy or do something (e.g., “the cost of housing is too high”) or the loss something requires or results in (e.g., “the war was won, but at the cost of many lives”).
As a verb, “cost” is usually a transitive and stative verb used to describe the price of something or the loss resulting from something (e.g., “her new suit cost $500,” “her credit card debt cost her her marriage”).
In professional environments, “cost” can be used as an action verb meaning to calculate how much something will be (e.g., “we need to cost the new project”). The simple past tense of “cost” in this context is “costed.”
Continue reading: Is cost a verb?
Stative verbs (aka state verbs) describe a state, condition, or perception. The state can be physical, mental, or emotional (e.g., “be,” “believe,” “love”).
Dynamic verbs (aka action verbs) describe an action carried out by or on the subject (e.g., “eat,” “throw,” “run”). The action can be cognitive or sensory as well as physical (e.g., “he is thinking about buying a house,” “she looked at the schedule”).
Some verbs can be either dynamic or stative depending on whether they are describing an action or a state.
Continue reading: What is the difference between stative and dynamic verbs?
We change regular verbs to the simple past and past participle forms by adding “-ed” (or “-d” if the verb already ends in “e”). For example, “talk” becomes “talked” and “dance” becomes “danced.”
Some regular verbs change their spelling in other ways, such as doubling the final letter or replacing “-y” with “-ied,” but they still follow predictable patterns. Regular verbs are always the same in their past and past participle forms.
Irregular verbs don’t follow the regular rule of adding “-ed” or “-d” to form the simple past and the past participle forms. They can change in a variety of ways or not change at all, and their simple past and past participle forms can be (but aren’t always) different.
For example, “go” becomes “went” in the simple past but is “gone” as a past participle, while “hit” is the same in all three forms.
Continue reading: What’s the difference between regular and irregular verbs?
Irregular verbs don’t follow the regular rules for forming the simple past tense and the past participle form. While regular verbs need the addition of “-ed” (or “-d” if the verb already ends in “e”), irregular verbs can change in a variety of ways or not change at all.
Here are some examples of irregular verbs in the simple past and past participle forms:
| Base form |
Simple past |
Past participle |
| be (is, am, are) |
was/were |
been |
| do |
did |
done |
| eat |
ate |
eaten |
| go |
went |
gone |
| sing |
sang |
sung |
When you’re conjugating irregular verbs into different verb tenses, QuillBot’s free Grammar Checker can help you avoid errors.
Continue reading: What are some irregular past tense verbs?
The past continuous tense (aka the past progressive) is a past tense verb form used to describe actions that were ongoing in the past. It often describes actions that were happening at the same time or that were happening when something else occurred.
Here are some examples of the past continuous tense:
- I was surfing when my surfboard broke.
- She was smiling as I was telling the story.
- We were singing karaoke while our friends were dancing.
- Jemal was always studying on Friday nights.
Continue reading: What are some examples of the past continuous tense?
“Was” and “were” are both simple past tense forms of the stative verb “be.” The correct form to use depends on the subject.
“Was” is used for most singular subjects, including first person and third person (e.g., “I was,” “she was”).
“Were” is used for plural subjects (e.g., “we were,” “they were”), but it’s also used for the second person regardless of whether the subject is singular or plural (e.g., “you were”).
Whether “was” or “were” is correct can also depend on whether you’re using the subjunctive mood or indicative mood. The subjunctive mood is used to express wishes, hypotheticals, and suggestions (e.g., “if I were you, I would say something”).
QuillBot’s Grammar Checker can help you ensure you’re using was and were correctly.
Continue reading: What is the difference between was and were?
Although “could of” is sometimes used in colloquial speech, the correct form is “could have” or the contraction “could’ve.”
“Could” is a modal auxiliary verb and “have” can either be an auxiliary verb or a main verb. Modals and auxiliaries are used with a main verb to change its tense, mood, or voice. When “could have” modifies a main verb, it means that something may have been possible in the past but didn’t happen (e.g., “we could have stopped for coffee if we’d left earlier”).
Continue reading: Is it “could of” or “could have”?
“Was,” like other forms of “be,” can either be a main verb or a helping verb (aka auxiliary verb). As a main verb, “be” is always a stative and linking verb (e.g., “I was a doctor”). As a helping verb, it helps to form the passive voice (e.g., “the house was sold”) and progressive tenses, such as the present progressive (e.g., “I was selling my house”).
Continue reading: Is “was” a helping verb?
The most common linking verbs are “be,” “become,” and “seem.” These are also known as “true linking verbs.”
Other common linking verbs include “appear” when it means “seem” and sensory verbs such as “taste,” “feel,” and “smell” (e.g., “this coffee tastes bitter,” “I feel good”).
Apart from “be,” “become,” and “seem,” all linking verbs can also be action verbs depending on whether they’re describing the state of the subject or an action.
Continue reading: What are some common linking verbs?
“Look” is a linking verb when it is describing a quality of the subject (e.g., “you look happy” or “the food looks good”).
When it is describing the act of looking at something, “look” is an action verb (e.g., “he looked at the TV”).
Continue reading: Is “look” a linking verb?
