A pessimist!

complaining, complaintive – expressing pain or dissatisfaction of resentment; “a complaining wife”

Antonyms: uncomplaining, patient, unmurmuring, unprotesting

Verb complain has 2 senses

complain, kick, plain, sound off, quetch, kvetch – express complaints, discontent, displeasure, or unhappiness; “My mother complains all day”; “She has a lot to kick about”

Antonyms: cheer, cheer up, chirk up

Derived forms: noun complaint3, noun complainer1

Sample sentence:

They complain that there was a traffic accident

complain – make a formal accusation; bring a formal charge; “The plaintiff’s lawyer complained that he defendant had physically abused his client”

–2 is one way to charge

Derived forms: noun complaint5, noun complaint4, noun complainant1

Sample sentence:

Somebody —-s that CLAUSE