Post a sheet of chart paper on the bulletin board and write a beginning sentence for a story. Write vocabulary words for the week (or words pertaining to a theme you are studying) around the edges of the chart paper. Students will add sentences to continue the story. They must include at least one of the vocabulary words in their sentence(s). You may have students add a sentence as part of the writing center, during independent work time, or any other appropriate period. You can make rules for the posting of the sentences, including how many sentences each student must have, the general theme of the story, inclusion of dialogue, or any other writing elements that they are studying at the time. This activity works well from beginning writers to the upper levels. Have the class share the story when it's finished. You may want students to rewrite these so you can eventually make a book of Class Stories.