Again, verb practice for all tenses you have studied. With emphasis on the "time" to use each tense. Students must use a verb, and an expression of time for each.

Student One: "Yesterday, I bought a sandwich for lunch".
Student Two: "Oh really? I always buy a sandwich".
Student 3 : "Oh really? I will probably buy one tomorrow".
Student 4: "oh really? Look at me, I am buying one right now".
Student 5: I would have bought one yesterday, had I had the money (advanced student, 3rd conditional)
and so on......then change the verb and go around again.