If your class doesn't like to participate that much and you want to wake them up, try this verbal activity.
What you do is put a chair in the front with the back of the chair to the board and divide the class into teams (I usually only do two). The first team sends one person to the front to sit in the chair. The teacher then writes a word on the board. Team one then tries to make the participant say the word without anyone in the team saying it themselves. The tricky part is that they cannot use ANY body language. The only way they can make this person say the word is by using synonyms or explanations. Here is an example...
The word is BLACK.
STUDENTS BEGIN BY SAYING... The opposite of white!
If the student says the word they get a point for their team. Each team has one minute to do this. A way to make it harder is by writting clues like the following...
BLACK AND WHITE
STOP AND GO
WHAT TIME IS IT?
Don't forget that if they use body language they lose and the next team goes. THIS IS VERY IMPORTANT... BE FAIR ABOUT TEAMS THAT USE BODY LANGUAGE. If they make the slightest movement call on it because if you don't you'll have an all-out war between you and the students. Other than that this is a great game and you'll have a lot of fun.
If you have students that love to yell try to flip the activity by having them use body language only and the person tries to guess what they are doing.