deceitfulmisleadingunreliable
You don't. If possible, get them out of your life. Trying to reason with an emotionally ill person (and pathological lying is an emotional disorder) is like trying to make grass grow by feeding the cat. There is no common ground.
Megalomaniac is a psycho-pathological disorder. Those who suffer from this disorder often have an inflated self-esteem and have delusional fantasies of power and relevance. Since the affected person is usually not interested in making changes, it is often treated by medication.
A pathological liar has an unhealthy need to avoid telling the truth. This disorder usually requires therapy to change the person's mental habit of lying. the person will tell a lie and believe the lie he/she is telling you regardless of the fact that they know it is a lie, thus to say convinces him or herself to believe it.
A person who constantly lies is typically referred to as a pathological liar or a compulsive liar. They may have a condition called pseudologia fantastica, which is a psychological disorder that prompts individuals to compulsively lie.
Imitation is when a person imitates another person that is not themselves. For example, they would imitate their gym teacher during the play.
"No, people who lie do it on purpose, and sometimes they lie for so many years when they are telling a story that is not true they may think it is because lying has become such a part of life they can't tell they are doing it anymore. The only cure is the person changing the bad habit." That's rather inaccurate. The term pathological lying essentially translates to uncontrollable lying. This can mean that a person who is suspected of pathological lying is considered to have a disease, and therefore cannot control the lying. However, psychologists and psychiatrists fail to account for a specific definition of pathological lying as a disease. It can be symptomatic of other conditions, like antisocial personality disorder, obsessive compulsive disorder (OCD) or attention deficit and hyperactivity disorder (ADHD). It is not always present in these conditions, so a clear treatment set for pathological lying has not been defined. Many people who exhibit pathological lying also clearly exhibit symptoms of other treatable conditions. Conditions like ADHD and OCD are treatable through medication, though different ones. This makes accurately diagnosing underlying conditions important. The last thing one would want to give a person with OCD is a stimulant like Ritalin, which would likely exacerbate their disorder. Personality disorders that contribute to pathological lying may also respond to a combined treatment of psychiatric medication and cognitive behavioral therapy. The goal with pathological lying must in the end be to treat any evidence of illness or conditions that may influence the lying. This may include medications and the use of behavioral therapy to help the person overcome compulsive lying.
Pathological liars may not always be fully aware of their condition, as they may believe their lies themselves. However, some may recognize that their lying behavior is problematic but struggle to control it due to underlying psychological factors. Overall, the awareness of their condition varies among individuals.
I am not familiar with the term Abnormal Movement Disorder. Perhaps you are referring to Tourettes Syndrom. Tourettes is a neurological disorder that normally appears in childhood. It involves involuntary movements of the limbs, and may also involve involuntary noises and sounds made by the person. I do not think there is any cure for it, and symptoms are normally mild.
Echolalia
There are many reasons why a person may have constant leg movement. It could be a nervous habit to constantly move their legs, or they could have a nerve or muscle disorder.
A pathological liar may try to manipulate others into believing that someone else is also a pathological liar by projecting their own behaviors onto that person. This manipulation can create confusion and sow distrust among individuals involved. It is essential to verify information independently and consider the motives of the person making such accusations.