Valency: The Chemistry of Verbs

Do you remember high school chemistry? You might recall staring at the periodic table, trying to memorize how atoms bond. You learned that Carbon has four electrons available for bonding, allowing it to grab onto four Hydrogen atoms to create Methane. Oxygen, being a bit more selective, only looks for two bonds to create water. In chemistry, this bonding capacity is called valency.

But what if I told you that language works exactly the same way?

Just as atoms differ in their ability to hook onto other atoms, verbs differ in their ability—and requirement—to hook onto nouns. In the linguistic laboratory, the verb is the nucleus, and the “arguments” (subjects and objects) are the electrons orbiting it. Understanding Verb Valency is the secret key to mastering sentence structure, whether you are analyzing syntax or learning a new language.

The Nucleus of the Sentence

To understand valency, we first need to look at the verb. In casual grammar, we often call the verb the “action word.” But in functional linguistics, the verb is the predicate—the structural center of the universe. The verb dictates everything else that happens in the sentence.

Think of a verb as a bossy project manager. A verb doesn’t just describe an action; it brings a specific number of empty chairs to the meeting room and demands they be filled. These empty chairs are what linguists call arguments.

If the verb doesn’t get the number of arguments it demands, the sentence “crashes.” It feels wrong. It sounds incomplete. It is chemically unstable.

The Valency Scale: From Zero to Three

Linguists categorize verbs based on how many arguments (participants) they require to form a grammatical sentence. Let’s look at the hierarchy of these grammatical bonds.

1. Avalent Verbs (Valency: 0)

Is it possible to have a verb that requires nothing? In English, this is tricky. We have a rule that says every sentence needs a subject. However, think about weather verbs.

Consider the sentence: “It rains.”

Ask yourself: Who is raining? Is there a giant clown in the sky named “It” performing the action? No. The word “It” is a “dummy subject” (or expletive). It has no meaning; it is just a grammatical placeholder. Semantically, the verb rain involves zero participants. It is an event that just happens. In many languages, like Spanish or Latin, you don’t even use the placeholder. You simply say “Llueve” (Rains).

2. Monovalent Verbs (Valency: 1)

These are the loners of the verb world. They are chemically stable with just one bond: the Subject. In traditional grammar, we call these Intransitive verbs.

• “John sleeps.”
• “The flower bloomed.”
• “She sneezed.”

If you try to add a second bond, the molecule falls apart. You cannot say “John sleeps the bed” or “She sneezed the tissue.” The verb sleep possesses a valency of one. It demands an actor, and once it gets one, the door is closed.

3. Bivalent Verbs (Valency: 2)

These are the social butterflies. They are unstable if they only have a subject; they desperately need an object to complete their meaning. We know them as Transitive verbs.

Consider the verb devour. If you walk into a room and say, “I devoured”, people will stare at you, waiting for the rest of the sentence. Devoured what? A sandwich? A book? The victory?

• “The cat chased the mouse.”
• “I broke the vase.”

Here, the verb bonds two arguments together: the doer (Subject) and the undergoer (Direct Object).

4. Trivalent Verbs (Valency: 3)

Now we reach the heavy elements. These are complex verbs that facilitate a transfer. They usually involve a Subject (the doer), a Direct Object (the thing involved), and an Indirect Object (the recipient). These are Ditransitive verbs.

The classic example is give.

“Sarah gave the dog a bone.”

• Argument 1 (Subject): Sarah
• Argument 2 (Indirect Object): The dog
• Argument 3 (Direct Object): A bone

Other verbs in this category include send, show, and tell. If you remove one of these elements, the sentence often feels awkward or changes meaning entirely.

Arguments vs. Adjuncts: The Optional Accessories

One of the hardest parts of analyzing sentences is distinguishing between what the verb needs and what is just extra decoration. This is the difference between Arguments and Adjuncts.

As we established, Arguments are the chemically bonded atoms required by the verb’s valency. Adjuncts, however, are optional. They provide background information like time, place, or manner. They are not chemically bonded to the verb; they are just floating nearby.

Let’s look at a monovalent sentence:

“Jesus wept.” (Grammatically complete. Valency satisfied.)

Now let’s add adjuncts:

“Jesus wept quietly in the garden yesterday.”

We added three new pieces of information, but the valency of the verb weep hasn’t changed. You can strip all those bolded words away, and the sentence remains stable. However, if you take a trivalent sentence like “I put the book on the table”, the phrase “on the table” is actually an argument, not an adjunct. You can’t just say “I put the book.” It sounds wrong. The verb put demands a location.

Why This Matters for Language Learners

You might be thinking, “This is fascinating linguistic theory, but how does it help me learn Spanish or Japanese?”

Valency is actually one of the biggest hurdles in second language acquisition. We often assume that a verb in our target language has the same “chemical properties” as the translation in our native language. This is rarely 100% true.

The “listen” trap:
In English, listen is technically intransitive. You cannot “listen the music.” You must “listen to the music.” The preposition “to” acts like a bridge because the verb can’t bond directly to the object.
However, in Italian, ascoltare is fully transitive. You say “Ascolto la musica” (I listen the music). An English speaker learning Italian might unnecessarily add a preposition, while an Italian learning English might drop it.

The “rain” trap:
As mentioned earlier, English requires a dummy subject for zero-valency verbs (It rains). A native English speaker learning Spanish might try to invent a subject for llueve, causing confusion. Conversely, Spanish speakers learning English often say “Is raining” (omitting the “It”), which violates the structural rules of English valency.

The Fluidity of Valency

Language is alive, and valency can sometimes shift. Through a process called valency reduction or expansion, speakers can manipulate verbs.

We can turn a transitive verb into an intransitive one through the Passive Voice.

Active: “The chef cooked the meal.” (2 Arguments)

Passive: “The meal was cooked.” (1 Argument – The agent has been removed).

We can also increase valency using Causatives.

Intransitive: “The baby eats.”

Causative: “The mother feeds the baby” (or “makes the baby eat”). We have added an agent, increasing the valency from one to two.

Conclusion

Next time you are reading a complex sentence or struggling to construct one in a foreign language, stop and look for the verb. Ask yourself: What is its chemistry? How many “electron slots” does it need to fill to be stable? Is it a loner like sleep, or a needy manager like put?

By viewing verbs not just as words that describe movement, but as the structural architects of the sentence determining who does what to whom, you move beyond memorizing vocabulary words and start seeing the invisible skeleton of language itself.