This activity is a great alternative to a worksheet. Post the cards around the room (on walls, board, desks, etc.) and have students work in pairs or individually.
Students can start at any stem changing verb near them.
Students read the subject pronoun-infinitive (at the bottom of the card) and record their answer (conjugated verb) on their answer sheet.
Then they will walk around the room to find the next card with the next clue. That card should have the same verb form they recorded on their answer sheet. Once they find this card, they will get their next question ... they read the next subject pronoun-infinitive at the bottom and repeat the steps explained earlier.
Students LOVE this activity!