This is an idea I'm going to try tomorrow.

True or false - one student leaves the room, then I hide a piece of candy. Three students are brought to the front of the room. The first student returns and asks them "Where is the candy?

Two lie, one tells the truth - the first student has to guess. If they guess correctly, they and the student who told the truth get candy, if they don't, the liar's get candy.

If the students aren't capable to coming up with their own true/false sentences you could suggest some to them or prepare cards for them in advance of the lesson.

True or false - one student leaves the room, then I hide a piece of candy. Three students are brought to the front of the room. The first student returns and asks them "Where is the candy?

Two lie, one tells the truth - the first student has to guess. If they guess correctly, they and the student who told the truth get candy, if they don't, the liar's get candy.

If the students aren't capable to coming up with their own true/false sentences you could suggest some to them or prepare cards for them in advance of the lesson.