The imperative form is one of the least difficult aspects of the English language to master, and teaching it provides a good opportunity for the instructor to broaden students' vocabulary of actionable verbs. Because it is used in commands and instructions, there is no shortage of games appropriate for learners of all ages for the instructor to draw upon. Simple ones can harness the energy of pre-schoolers, while complex ones stretch the abilities of adults.
The familiar children's game of "Simon Says" is a natural candidate for adaptation for use in the English classroom. Instead of mimicking actions, however, students respond to verbal instructions -- for example: "Simon says: Put your hand on your head." It functions well strictly as a listening and comprehension exercise either with the teacher or selected students giving instructions. It's a good way to teach vocabulary related to the body, and may turn quite raucous as more creative students think of ways to contort the bodies of their classmates into improbable shapes.
As an activity that can be conducted in pairs, groups or with the whole class, "Draw This" is a game that an instructor can use to consolidate the imperative form while incorporating practice in understanding abstract forms and processes. One student either draws a picture or finds one in a book and instructs others in reproducing it. Simple pictures work best for beginners and young children, while more complex ones are more appropriate for advanced learners and those who are studying English as part of a technical or design curriculum.
"Dear Abby" is primarily a game for adults, although some younger learners may also be able to play it under the right circumstances. Students in pairs or in a group decide who is Abby, then describe a problem, such as "I have a hard time sleeping at night." Abby then offers instructions to remedy the problem. It's a game that works well in a conversation-oriented ESL because it helps to break the ice between learners who may not have much contact outside the classroom. Students offer the content, freeing the instructor to focus on grammar points and pronunciation.
Do You Know the Way
Any English learner will be confronted at some point in life with the need to give directions, and practicing in the English classroom is also a good exercise in the imperative form. In pairs or groups, one student asks: "Do you know the way to...," filling in the blank with a familiar or obscure local landmark. Another student answers with directions, forming the sentences as commands: "Turn left at..." or "Walk three blocks." A passive listening variation is to give students a map and have them pinpoint a location on directions from the instructor or a student.