Divide the students into teams, and ask questions about how to use the imperfect progressive tense. Award points to the team who gets the correct answer, and give a small prize to the winning team at the end. Another option is to set up a Jeopardy! board where you incorporate all of the different Spanish tenses. The students have to distinguish one tense from another or say a particular sentence using the proper tense and words.
Bring the students to the computer lab to work on activities on the imperfect progressive on the Internet. Have them try one of the Hangman Verb Conjugation Games at Elma Eagles (elmaeagles.com/spanish.htm). Another source for games is 123 Teach Me's Imperfect Progressive website (123teachme.com/learn_spanish/progressive_tense_3_intro) where students find flashcards, funny photos, drag and match games, puzzles and other interactive games to enhance their knowledge of the Spanish language.
Have one student come to the front of the classroom and pick a card with a sentence written in the imperfect progressive. The student then acts out the sentence to the rest of the class, and they must guess what he is doing. However, they have to use the imperfect progressive tense when they guess the answer. Whoever guesses correctly gets to draw next.
Have the students make presentations that involve the imperfect progressive tense. Divide the students into groups and have each group reteach a different tense, the imperfect progressive being one of them, to the rest of the class at the end of the year. Have the students make a video where they speak in Spanish and are required to use the imperfect progressive tense at least 10 times throughout the course of their video. Show the films to the class.