The Parts of Speech System
Lesson: 3 of 9 — Verbs: Action and State
Lesson: 3 of 9 Level: 🔵 Beginner
1. Lesson Overview
If nouns are the words we use to name the world, verbs are the words we use to say what happens in it. Every sentence in English must contain a verb. Without one, there is no sentence — only a fragment, a label, a still photograph rather than a moving picture.
Verbs do an enormous amount of work in English. They tell us what someone or something does, what state something is in, and when all of this happens. They carry tense, they signal agreement with the subject, and they combine with other verbs to express meanings as precise as obligation, possibility, habit, and regret.
This lesson introduces the verb in its main forms and functions. The tense system, modal verbs, and the passive voice are each explored in dedicated modules later in the course — but everything in those modules depends on a clear understanding of what a verb is and what it do
Objectives
By the end of this lesson, you will be able to:
- Define a verb and explain its central role in a sentence
- Distinguish between action verbs and stative verbs
- Identify the main types of verbs in English
- Recognise and correct common errors in verb usage
2. Core Content
2.1 Defining a Verb
A verb is a word that expresses an action, an event, or a state. Every grammatical sentence in English contains at least one verb. The verb is the core of the predicate — the part of the sentence that says something about the subject.
Consider the following sentences:
The Earth orbits the Sun once every 365.25 days. Antarctica contains approximately 70 per cent of the world’s fresh water.
In the first sentence, orbits expresses an action — the movement of the Earth around the Sun. In the second, contains expresses a state — a condition that exists rather than an event that happens. Both are verbs, and both are essential to the meaning of their sentences.
2.2 Action Verbs and Stative Verbs
One of the most important distinctions in English is between action verbs and stative verbs.
Action verbs
An action verb describes something that a person, animal, or thing physically or mentally does. Actions can be observed or performed.
For example:
Valentina Tereshkova orbited the Earth 48 times in 1963. The tectonic plates move several centimetres every year.
In both sentences, the verbs — orbited and move — describe things that physically happen. They express events unfolding in time.
Stative verbs
A stative verb describes a state or condition rather than an action. States are not events; they are ongoing situations. Common categories of stative verbs include verbs of perception, emotion, cognition, and possession.
| Category | Examples |
|---|---|
| Perception | see, hear, smell, taste, feel |
| Emotion | love, hate, fear, prefer, want |
| Cognition | know, believe, understand, think, remember |
| Possession | have, own, possess, belong, contain |
| Being | be, seem, appear, exist, resemble |
For example:
Scientists believe that the universe is approximately 13.8 billion years old. The Pacific Ocean contains more water than all other oceans combined.
In the first sentence, believe is a stative verb — it describes a mental state, not an action. In the second, contains is a stative verb expressing a condition. Neither can normally be used in the continuous form: we do not say scientists are believing or the ocean is containing.
2.3 Main Verbs and Auxiliary Verbs
English sentences often contain more than one verb. In such cases, there is a distinction between the main verb and any auxiliary verbs that support it.
Main verbs
The main verb carries the core meaning of the sentence. It tells us what the subject does or what state it is in.
Auxiliary verbs
Auxiliary verbs — sometimes called helping verbs — work alongside the main verb to express tense, aspect, voice, or mood. The primary auxiliary verbs in English are be, have, and do. Modal auxiliary verbs — such as can, will, must, and should — express meanings such as ability, certainty, obligation, and permission.
| Auxiliary Verb | Function | Example |
|---|---|---|
| be | Forms continuous and passive constructions | The ice caps are melting at an accelerating rate. |
| have | Forms perfect constructions | Researchers have discovered a new species of deep-sea fish. |
| do | Forms questions and negatives | Coral reefs do not recover quickly from bleaching events. |
| can | Expresses ability or possibility | Some bacteria can survive in extremely acidic environments. |
| must | Expresses obligation or certainty | Astronauts must undergo years of rigorous training. |
| will | Expresses future time or certainty | Global temperatures will continue to rise without intervention. |
For example:
Astronomers have observed more than 5,000 exoplanets beyond our solar system. The results of the experiment were published in a leading scientific journal.
In the first sentence, have observed consists of the auxiliary verb have and the main verb observed. Together they form the present perfect tense. In the second, were published consists of the auxiliary verb were and the main verb published, forming the passive voice.
2.4 Transitive and Intransitive Verbs
Verbs can also be classified according to whether they require an object to complete their meaning.
A transitive verb requires a direct object — a noun or noun phrase that receives the action of the verb. An intransitive verb does not take a direct object; it is complete without one.
| Transitive | Intransitive |
|---|---|
| Darwin studied barnacles for eight years. | The volcano erupted in 1980. |
| Galileo observed the moons of Jupiter. | The population has grown steadily. |
| Marie Curie discovered radium. | The river floods every spring. |
For example:
Isaac Newton developed the laws of motion in the 17th century. The comet appeared in the night sky and disappeared within a week.
In the first sentence, developed is transitive — it takes the laws of motion as its direct object. In the second, both appeared and disappeared are intransitive — neither takes an object. Some verbs can be both transitive and intransitive depending on context: The chef cooked (intransitive) / The chef cooked the fish (transitive).
2.5 Linking Verbs
A linking verb connects the subject of a sentence to a word or phrase that describes or identifies it. Rather than expressing an action, a linking verb expresses a relationship between the subject and its complement. The most common linking verb is be, but others include seem, appear, become, remain, feel, look, sound, smell, and taste.
For example:
The Sahara is the largest hot desert on Earth. The surface of Mars appears red due to iron oxide in the soil.
In the first sentence, is links the Sahara to its description. In the second, appears links the surface of Mars to the description red. Note that after a linking verb, we use an adjective or a noun, not an adverb: we say the soil smells rich, not the soil smells richly.
2.6 Regular and Irregular Verbs
English verbs form their past tense and past participle in two ways.
Regular verbs add -ed to form both the past tense and the past participle.
| Base Form | Past Tense | Past Participle |
|---|---|---|
| explore | explored | explored |
| discover | discovered | discovered |
| measure | measured | measured |
Irregular verbs change their form in unpredictable ways and must be learnt individually.
| Base Form | Past Tense | Past Participle |
|---|---|---|
| rise | rose | risen |
| write | wrote | written |
| begin | began | begun |
| grow | grew | grown |
| speak | spoke | spoken |
For example:
Temperatures rose sharply during the last interglacial period. Scientists have written extensively about the effects of deforestation.
In the first sentence, rose is the irregular past tense of rise. In the second, written is the irregular past participle of write, used here to form the present perfect tense.
3. Usage in Context
| Rule | Example |
|---|---|
| Every grammatical sentence must contain at least one verb. | The Amazon flows east. (flows = verb) |
| The verb must agree with its subject in person and number. | The river rises every rainy season. / The rivers rise every rainy season. |
| Stative verbs are not normally used in continuous tenses. | The lake contains fresh water. (not is containing) |
| Action verbs can be used in both simple and continuous tenses. | Glaciers melt every summer. / Glaciers are melting faster than before. |
| The auxiliary verb do is used to form negatives in the simple present and simple past. | The moon does not have an atmosphere. |
| The auxiliary verb have combines with the past participle to form perfect tenses. | Scientists have mapped the entire human genome. |
| The auxiliary verb be combines with the present participle to form continuous tenses. | The population of the world is growing by approximately 80 million people per year. |
| The auxiliary verb be combines with the past participle to form the passive voice. | The theory of evolution was proposed by Charles Darwin in 1859. |
| Transitive verbs must be followed by a direct object to complete their meaning. | Astronomers discovered three new exoplanets. (not Astronomers discovered.) |
| Intransitive verbs cannot take a direct object. | The earthquake occurred at a depth of 10 kilometres. (not The earthquake occurred the ground.) |
| After a linking verb, use an adjective — not an adverb — to describe the subject. | The water tastes fresh. (not freshly) |
| Modal auxiliary verbs are always followed by the bare infinitive. | Temperatures can reach 50°C in the Sahara. (not can to reach or can reaches) |
| Regular verbs add -ed to form the past tense and past participle. | Explorers mapped the coastline of Australia in the 18th century. |
| Irregular verbs must be learnt individually; their forms do not follow a standard pattern. | The Nile flooded its banks annually until the Aswan Dam was built. |
| Some verbs function as both transitive and intransitive verbs depending on context. | The ice melted. (intransitive) / The sun melted the ice. (transitive) |
| Phrasal verbs — combinations of a verb and a particle — often have idiomatic meanings that differ from their individual parts. | Scientists are carrying out research into the effects of microplastics on marine life. |
| In formal and academic writing, phrasal verbs are often replaced with single-word equivalents. | carry out → conduct / find out → discover / go up → increase |
| The past participle is used in perfect tenses, the passive voice, and as an adjective. | The data collected over fifty years shows a clear warming trend. |
| Verbs of perception — see, hear, feel — can be followed by either the bare infinitive or the present participle, with a difference in meaning. | I heard the volcano erupt. (a complete event) / I heard the volcano erupting. (an ongoing process) |
| Avoid using got as a past participle in formal writing; use become or been instead. | The results became clear after further analysis. (not got clear) |
4. Common Errors and Corrections
| Error ❌ | Correction ✅ | Explanation |
|---|---|---|
| She is knowing the answer. | She knows the answer. | Know is a stative verb and cannot be used in the continuous form. |
| The scientist has went to Antarctica. | The scientist has gone to Antarctica. | Gone is the past participle of go; went is the simple past and cannot be used with has. |
| Water consist of hydrogen and oxygen. | Water consists of hydrogen and oxygen. | The verb must agree with its subject; water is third person singular and requires consists. |
| The results were surprising and interested many researchers. | The results were surprising and interested many researchers. ✓ — but note: The researchers were interested uses interested as an adjective after a linking verb, not as an action verb. | This entry clarifies a common confusion between interesting (describing the thing) and interested (describing the person’s reaction). |
| He become a leading expert in climate science. | He became a leading expert in climate science. | Become is irregular; its past tense is became, not become. |
| The committee are decide the outcome tomorrow. | The committee will decide the outcome tomorrow. | Are decide is not a grammatical construction; the future here requires will + bare infinitive. |
| She suggested to attend the conference. | She suggested attending the conference. | Suggest is followed by a gerund, not a to-infinitive. |
| The river has froze during the coldest winters on record. | The river has frozen during the coldest winters on record. | Frozen is the past participle of freeze; froze is the simple past and cannot follow has. |
| Darwin were a naturalist who changed scientific thinking. | Darwin was a naturalist who changed scientific thinking. | Darwin is singular; the past tense of be for singular subjects is was, not were. |
| The temperature is feeling cold today. | The temperature feels cold today. | Feel in the sense of temperature or sensation is a stative verb and does not take the continuous form. |
5. Lesson Mastery
After completing this lesson, you should now be able to:
✅ Define a verb and explain its central role in a sentence
✅ Distinguish between action verbs and stative verbs
✅ Identify the main types of verbs in English
✅ Recognise and correct common errors in verb usage