There are numerous tell tail signs that are easy to read when you know someone is lying.
The bottom of the pile and the most obvious sign, although this is a sign of a really poor liar is arguing over semantics in order to try and negate the fact they have been caught in the act so to speak.
This takes many forms, normally quibbling over the initial accusation by faulting of the wording of the question to which they have lied to. For example:
I didn’t lie, you asked blah blah, not blah blah. What is being inferred by the question is the same for all to see. I would liken this to hiding in plain sight.
The wording may be slightly different but the intent of the question was the same as is plain to see. This is what the liar will fall back on time and again as a poor excuse to avoid being labeled a liar.
Then there are other semantics.
Such as when the lair denies doing something based on the fact that they did not strictly do what they are being accused of. You see the trick in every piss poor court room drama. ie they are asked a question and by not answering it they infer a positive response. In this case they can deny they have answered a question but have in fact done so by not issuing an answer. Again, plain for all to see, but a good way of leaving yourself the sly exit of being able to say, ‘But I didn’t say anything when asked’.
These are just some examples of the way a poor liar will try and wriggle out of actually admitting to having lied when it is obvious to all and sundry.