The person is constantly complaining
Toxic people are dissatisfied with everything and everyone. They are hard to please and, as a result, all you can hear from such people is a ton of complaints. They express their negative attitude. They are not playing – that’s their true nature and they do not realize that their behavior is terrible.
The person runs down other people
It is so typical of a toxic person to talk crap about everyone. They love gossip and they usually exaggerate the bad side of things. It seems that for a toxic person talking negative stuff about others is their goal – this is how they feel more successful. If you know the person talks to you and tells you something bad about another person, it is very likely that he talks negatively about you behind your back.