Come up with lists of grade-appropriate verbs, nouns, adjectives and prepositions, which the class has seen before and can use in a sentence. Each list can be anywhere from ten to thirty words long, depending on the size of the class and the intended length of the game.
Separate the flashcards into piles by color. Starting with the first color, write a noun from the list on each card. On each card of the next color, write a verb. Write an adjective on each of the cards of the next color and a preposition on each of the remaining cards.
To play the game, bring the cards into the classroom, still separated by color. Have one group of students take a card from the noun pile, another group from the verbs, another from the adjectives and another from prepositions. Instruct the students to choose one of their cards, then set out into the class to find three people whose cards make a full sentence.
The game can be repeated by having students choose new cards. To extend the game, have students discuss ways to change the sentence, either by adding words, changing the order or putting sentences together with commas or semi-colons.