The difference between joking and telling the truth.

Truth is more specific than falsehood, and pleasantries have their own fixed expressions. For example, someone says to you, "Come to my house when you are free!" In this case, there are many pleasantries, and people may not really want you to visit, which means it may be deceptive. But if he says, "Are you free this Sunday? Come to my house, I have prepared your favorite braised fish. " In this case, people basically invite you to his home sincerely. The second expression adds the specific time "Sunday" and the specific thing "braised fish", and the tone is also a euphemism for asking about the will, indicating that it is both true and polite. The reason why the expression of falsehood is vague is because the liar doesn't want his falsehood to be exposed, so he will try to avoid more specific and detailed expression. Politeness is more of a polite expression, true or false. The above differences are only unilateral, and more often, we should consider the relationship between the speaker and himself, familiarity, age gap and so on. For example, in the first case, if the speaker knows himself well, it may be true.