I've found taking the iPad away works for my SD6. But if your son doesn't watch TV maybe he's not into tablets and such either.

I would give him a warning first. Talk to him and ask him how he would feel if you lied to him and he felt like he couldn't trust you. Kids need to be able to relate to people's feelings. I would then tell him that since he's been lying you're going to be checking into his answers for a while, and you will be less angry if he tells the truth about something than if you find out he's lying. Then if he continues, take things away or whatever suitable punishment you think suits him, and explain why.

Also ask him why he lied. Get to the bottom of it. "Because I didn't want you to get mad at me" "I wouldn't have been as upset with you if you had told me the truth. When you lie, it makes me very disappointed and I can't trust what you tell me.

Are you religious? If so....Maybe come at it from that angle. Teach him the 10 commandments and about how lying breaks one of those commandments. You never know. It might help some.

Your mom sounds awesome! lol

If I find that BS5 has done something wrong I will ask him about it, and before he answers reiterate calmly and firmly that he should remember that it is always better to admit what you have done and apologise, than to lie about it and make it worse. The reminder right before he speaks often prompts him to confess. At which point I will commend him for deciding to tell the truth, and explain that the consequence will be not be as bad as a result. Without the reminder the instinctive tendency to cover up and avoid getting into trouble seems to take over. If he does still lie about it then I'll outline the consequence, and explain that if he had been honest and apologised then the punishment would have been x, but because he chose to lie about it and make it worse the punishment is y (which is something worse than x).

I think you also have to try to crack down on each incidence to nip it in the bud and stop it becoming a habit. My YSD was an awful liar, it started with small things, which DH would often turn a blind eye to or dismiss as unimportant because he didn't want to be the bad guy and ALWAYS gave her the benefit of the doubt, and escalated to really serious lies about where she had been and what she was doing. She ended up thinking she was very clever because she could get out of anything. Even when confronted with the most damning evidence she would argue black was white and be frighteningly convincing. I ended up unable to believe anything she said and have a horror of my own children ending up that way.

As a punishment you could use something traditional like writing out lines, or extra chores, or losing some kind of privilege like playtime or treats.

Not a punishment, but you could tell him the story of the boy who cried wolf and how no one believed him when it mattered because of all of his lies. If you did that and had a chat with him about why he lies and ask him how that affects him and others and how does he think other people feel when he lies. Then let him know that his teacher and you guys want the lying to stop because it is bad and if he lies again he will face whatever punishment you decide on.

Personally I would attach a single immediate punishment to each case of lying rather than "grounding". Get the teacher to email you a report of any lies that he tells at school so that he can have a punishment that night at home. Grounding a first grader doesn't really work in my opinion. Maybe a time out (or earlier bed time?) and taking away one of his toys for each lie? He can earn them back for each day he is good with no lies and does everything that is asked of him.