Can you ever again trust a liar? I have an acquaintance that has lied so much, when she talks, I just "look at her" no words. I leave.

I don't think I'll ever really trust them again for a while but I will give them a chance to atone for their lie. If it continues, then I distance myself from them as much as I can. But I always give them another chance in case they learned their lesson about lying !

Nope. Some people live by the lie.

Not usually.

Lying is mostly impulsive and often someone who lies will have it set as the a default to their personality. Whether it is to gain favor, or make themselves look good, or even if their variation of what happened differs based on their skewed version of reality. Those whom take the time and cognitively  plan out and work their lies are just a bit more insidious.

I know everyone lies here and there, so it would depend on the severity of the lie and if they cause harm to others, or are told to progress a persons place in a circle of associates.

As example, If a person wakes up late for work, they often time make up a story, like "My cat knocked the glass bottle of oil off my kitchen counter and I had to clean it up before I left for work", as long as it is not chronic is harmless, especially when the person is nearly never known to be late for work.

Where-as, someone that is chronically late for work and makes up stories as to why, is actually causing harm, by their work having to addressed by others. These others most likely have their own projects to finish and then having to stop their own project to cover the chronic tardy person puts everyone's work behind.

Often lies can cause severe harm by putting others in a bad light to his/her peers, when it is not deserved, and can cause them harm. Some of these can be being passed over for a promotion, or a raise, due to a lie being told about their actual performance.

It's really best to be honest, and take the consequences.