Here's an activity specifically designed for elementary students that works very well to
teach/review form (paradigms), not function (contextual language).
Choose 10 irregular present tense verbs; e.g., run, hit, go, etc, and write them either on the board or on cards, and place the words on the board so that they run the length of the board, like this: (Don't number the cards, though)
|1 run |2 hit |3 go|4 cut |5 feel |6 fly |7 see |8 sing |9 sit |10 win|
Divide the class into two teams. Have one member from each teach come to the board. Have the student from Team A stand at the word |1run| and have the student from Team B stand at the word |10 win|. On the word "Go!" each student walks the line, calling out each verb like so, "run, ran"; "hit, hit"; "go, went" and so on until both students meet up on the same word.
When the two students meet, they play Rock-Paper-Scissors, and the winner stays where s/he is and the loser goes back to the team and another team member goes up to the board and starts at the beginning, either at |10 win| or |1 run|. (That is, if Team A started at |1 run|, then they always start on that side of the board; if Team B started at |10 win|, then they always start at that end of the board. If the student from Team A won Rock-Paper-Scissors on the word |4 cut|, then that students starts from there; the new player starts from |10 win|. Second round: at the word "Go!", the players begin again, calling out the words, and making their way to the end of the list. Team A starts at |4 cut| and Team B starts at |10 win|.
The first person to make it all the way to the end of the board wins the game. One of the beauties of this game is that every member in each team will be watching the other team's players to see if they slip up, make a mistake.
Try the activity out and see how much fun it can be!
Extension: teaching contextual language
1. Have the students give example sentences; e.g., I ran home; I did my homework; I went to school.
2. Don't use words, use pictures, and have the students make up a sentence. Don't review the pictures. Make it a surprise, a challenge; allow the students to be imaginative, creative.
Other ideas:
Don't use words or pictures, use the first letter of a given verb; e.g., the letter S could be see/saw, send/sent, etc., so either answer is correct. The idea is to get the students to encode language in more than one way.
UsingEnglish irregular verb list
irregular verbs, irregular students! 
Linear Mode
