Impersonal verbs are verbs that do not use a specific subject but instead use the generic subject it.
Definition
Impersonal verbs are those that employ the general subject rather than a particular subject.
Impersonal verbs don't employ what's known as a "determinate subject," which is a subject that describes something particular, such as the person or item doing an action, in contrast to other verbs. Instead, they frequently employ the neutral pronoun it, which doesn't stand for anything specific. Impersonal pronouns, then, do not describe who or what performs the action; rather, the action merely occurs.
Examples
Impersonal verbs frequently relate to the weather or other abstract concepts, such as light and darkness, but they may also be employed with idioms or everyday expressions, which we shall discuss later.
For example:
The weather is mentioned in the majority of impersonal verbs, but not all. Certain idioms and expressions transform verbs that would often be considered personal and impersonal verbs, for example:
Note
Keep in mind that impersonal verbs and their noun forms should not be confused. For instance, the impersonal verb snow, in this case the mass noun snow, can likewise be employed as a noun. Despite having the identical spelling, the verb snow and the noun snow have quite distinct purposes, therefore you must take this into consideration.