Complain is a verb.
"Complaining" can function as a verb or a gerund, depending on its context in a sentence. It typically serves as an action (verb) or a noun form of the action (gerund) related to expressing dissatisfaction or grievances.
free speech?
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "explicit" is an adjective.
The part of speech for "twirl" is a verb.
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "lecturer" is a noun.