Helping Verbs And Linking Verbs

Understanding the difference between helping verbs and linking verbs

I spent years grading student essays where people couldn't tell these two apart. It shows in the writing immediately. You need to know the difference because it changes how you structure a sentence and how you read one. Helping verbs, also called auxiliary verbs, work with a main verb to create a complete verb phrase. The main ones are forms of "be," "do," and "have," plus the modal verbs like can, could, will, would, shall, should, may, might, and must. They don't carry meaning on their own in that context. They help the main verb show tense, mood, or voice. Linking verbs are different entirely. They don't show action. They connect the subject to a subject complement, which is either a noun or an adjective that renames or describes the subject. The most common linking verb is "to be" in all its forms, but there are others. Sense verbs like seem, appear, look, feel, taste, smell, and sound can function as linking verbs when they describe the subject rather than show an action. Words like become and remain are also linking verbs.

Here's where it gets tricky for most people. The verb "be" can do both jobs depending on what follows it. "She is running" uses "is" as a helping verb because "running" is the main action verb. "She is tired" uses "is" as a linking verb because "tired" describes "she." Same word, completely different function. I remember working with a client who was translating technical documentation from German to English. The German verbs carried aspects of modality and tense in ways that didn't map cleanly onto English helping verb constructions. We spent three days debugging a sentence where the meaning shifted depending on whether we used a perfect tense with "have" or a progressive with "be." The workaround was to stop translating verb-by-verb and instead identify the core meaning first, then rebuild the English verb phrase around that meaning. That approach saved us from making hundreds of small errors that would have accumulated into something completely incomprehensible.

How to tell them apart in practice

The substitution test is the most reliable method. If you can replace the verb with a form of "to be" and the sentence still makes sense grammatically, it's functioning as a linking verb. "The soup smells good" becomes "The soup is good." That works, so "smells" is linking here. "He smells the soup" becomes "He is the soup." That makes no sense, so "smells" is an action verb in that sentence. For helping verbs, look for the main verb that follows. If there's a present participle, past participle, or base form verb after the auxiliary, you're dealing with a helping verb. "They have eaten" has "eaten" as the main verb and "have" as the helper. "She will go" has "go" as the main verb and "will" as the helper. A counter-intuitive thing about linking verbs: you can't modify them with adverbs the way you modify action verbs. You don't say "The soup smells deliciously" when you mean it tastes good. "Deliciously" would modify the act of smelling, not the soup itself. You use the adjective "delicious" because the linking verb connects to a subject complement. This trips up even advanced writers who've never had it pointed out to them.

Another nuance that beginners miss is that not all forms of "to be" are created equal. The verb "being" can function as a linking verb in continuous contexts, but it also appears in passive constructions where it's part of a helping verb phrase. "He is being difficult" uses "being" as a linking verb. "He is being questioned" uses "is" as a helping verb and "questioned" as the main verb in a passive construction. The distinction matters for parsing sentences quickly. There are scenarios where this system breaks down completely. Phrasal verbs with "be" followed by a preposition create ambiguity that the substitution test can't always resolve. "She is in the room" looks like it could be linking, but "in the room" is a prepositional phrase functioning as an adverb of place, not a subject complement. There's no noun or adjective renaming or describing "she." In these cases, the verb isn't linking and isn't really helping either. It's just a full verb on its own. Don't force the framework where it doesn't fit. If you're learning this, don't memorize lists. Practice the substitution test on sentences until it becomes automatic. Read sentences out loud and ask yourself whether the verb is showing action or connecting to a description. The first approach takes about two weeks of daily practice to feel natural. After that, you'll catch errors instinctively instead of working through rules every time.