A performative verb is a verb that names its own implementation. In other words, when an English speaker uses a performative verb, they “do” what they are describing simply by saying the verb. For example, when someone makes a verbal claim to something by saying “I claim this…” it is an example of a performative verb.
Performative verbs often describe an “action” that is verbal. A wide array of these “actions” apply to the English language. For example, there are many performative verbs related to the idea of “asserting” or “stating” something. Many of these are not as commonly used in English as they used to be. Also, when used in modern English, they are less likely to function as performative verbs. Some examples of performative verb phrases that English speakers used to use are “I declare that…,” “I avow…,” and “I affirm…”
Some other types of performative verbs relate to negative principles. For example, if someone says “I deny it” in reference to some accusation, they are using “deny” as a performative verb. The phrase “I denounce…” is also this sort of verb, but again, this phrase is not likely to be used in many modern English speaking communities.
In general, performative verbs were much more common in past eras when the idea of announcing one’s own actions was in style in the English language. Today, English speakers are less likely to verbally describe their thoughts this way. Some residual uses of performative verbs can be found in formal legal proceedings, for example, where someone may swear an oath. The use of “I swear” to swear or affirm something is performative.
Some uses of performative verbs are more colloquial than technical. For example, one such verb that has survived the ages is in the phrase “I tell you…” which usually precedes the act of telling someone something. Here, the addition of the phrase is not important to semantic meaning. It is more like an exclamation or a filler in speech. Still, this is a significant example of the way that these types of verbs are still used in the English language. Another interesting example is the use of the phrase “I guess” – some do not consider this to be technically performative, but it generally fits the mold for these types of verbs, as do other phrases, like, "I believe," or, "I feel.".