Is Should Be a Linking Verb? Grammar Rules Explained

Yes — is is a linking verb. It is a form of the verb to be, and it links the subject of a sentence to a word or phrase that describes or identifies that subject. In “She is a doctor,” is connects “She” to “a doctor”; it does not express an action. So when people ask whether “is should be a linking verb,” the answer is that is almost always behaves as one — the only major exception is when it appears before another verb as a helper, as in “She is running.”

What Is a Linking Verb

A linking verb connects the subject of a sentence to a subject complement — a word or phrase that renames or describes the subject. Merriam-Webster defines linking verbs as verbs that connect a subject with a word or words that identify or describe it. The most common linking verb in English is be, and all of its forms — am, is, are, was, were, been, being — can serve this role.

The core function is connection, not action. When a verb links, the sentence follows this pattern:

Subject + linking verb + subject complement

The subject complement can be:

• A predicate noun that renames the subject: “Marcus is a carpenter.” (carpenter = Marcus)
• A predicate adjective that describes the subject: “The soup is cold.” (cold describes the soup)

How ‘Is’ Functions

Is is the third-person singular present tense of to be — the form used with he, she, it, and singular nouns. Britannica notes that be is the most irregular and one of the most frequently used verbs in English, and its linking use is central to how the language works. Because is carries no action meaning on its own, it depends on the complement to complete the thought.

Here are clear examples:

• “The sky is blue.” — is links “The sky” to the adjective “blue.”
• “My sister is an engineer.” — is links “My sister” to the noun “an engineer.”
• “This is the answer.” — is links “This” to “the answer.”
• “The meeting is at noon.” — is links the subject to a phrase telling where or when.

The Subject Complement Test

To confirm is is linking, look at what follows it. If the next word or phrase describes or identifies the subject, is is a linking verb. If the next word is an -ing or past participle verb, is is probably a helping verb instead.

• Linking: “The cake is delicious.” (delicious describes the cake)
• Linking: “He is my neighbor.” (my neighbor identifies him)
• Helping: “The cake is baking.” (is + baking = a continuous action)

Linking vs Action Verbs

The clearest way to understand is is to contrast it with action verbs — verbs that express something the subject does, such as run, write, throw, think, laugh. Action verbs answer the question “What is the subject doing?” Linking verbs answer “What is the subject?”

Notice that is never expresses movement, effort, or activity. That is why is is not an action verb — it is a state-of-being verb. Some verbs can be either linking or action depending on the sentence. Taste is a good example: “The soup tastes salty” (linking — salty describes the soup) versus “She tastes the soup” (action — she performs the act of tasting). Is is simpler: it is a linking verb unless it is acting as a helper.

Linking vs Helping Verbs

This is where confusion most often arises. Is serves two distinct jobs:

1. Linking verb (used alone). When is stands by itself and is followed by a noun or adjective, it links the subject to a complement:

• “The door is open.”
• “She is happy.”

2. Helping (auxiliary) verb (used before another verb). When is appears before a main verb, it helps form a tense or voice rather than linking:

• “She is running.” (is + running = present continuous)
• “The report is being reviewed.” (is + being reviewed = passive voice)
• “He is going to call.” (is + going to = future meaning)

In these helping-verb cases, is does not link the subject to a complement; it modifies the main verb instead. Cambridge Dictionary explains that auxiliary verbs like be combine with main verbs to form continuous tenses and passive constructions.

So the reliable rule is: if a verb follows is, it is a helper; if a noun or adjective follows is, it is a linking verb.

Worked Example

Take the sentence: “The teacher is patient.”

• Subject: The teacher
• Verb: is
• What follows: patient (an adjective)
• Result: is links the subject to a description → linking verb

Now change it: “The teacher is grading papers.”

• What follows is: grading (a verb)
• Result: is helps form the continuous tense → helping verb

Same word, two functions — and the deciding factor is always what comes after it.

Special Constructions with ‘Is’

A few fixed patterns use is in ways that initially look unusual but still reflect its linking nature.

• Existential there. “There is a problem.” Here there is a placeholder, and the real subject is a problem.
• Cleft sentences. “It is the price that worries me.” Is links it to the price while the clause emphasizes the focus.
• Idiomatic phrases. “Time is money,” “Seeing is believing” — both follow the subject + linking verb + complement pattern exactly.

Recognizing these constructions prevents the mistaken conclusion that is is doing something other than linking.

Key Takeaways

• Yes, is is a linking verb. It is a form of to be and links the subject to a subject complement that describes or identifies it.
• A linking verb connects; it does not show action. “She is a doctor” describes, while “She runs” shows action.
• Is links when followed by a noun or adjective: “The soup is cold,” “He is my neighbor.”
• Is becomes a helping verb when followed by another verb: “She is running,” “The report is being reviewed.”
• The simple test: look at what follows is. A noun or adjective signals linking; another verb signals helping.