Change places if ... (otherwise known as Fruit Salad)
Chairs should be arranged in a horseshoe for this. The teacher should start by saying something like "Change places if you like chocolate". All students who would answer 'yes' must get up and run to a new chair. The teacher should attempt to sit down in one of the empty chairs. The last student standing must now say "Change places if ..." and attempt to get a seat. Repeat until everyone is hot and sweaty.
There are a few variants on this activity.
Variant 1: Put the students in two teams, in two lines up to the board. The first student in each team has the pen (a different colour for each team). The teacher writes the letters A-Z on the board in two or three columns, and writes the category on the board (e.g. 'jobs'). The students race to write up a word for each letter (e.g. jobs - architect, builder, ...), then hand the pen to the next student. They don't have to do the letters in order. Stop after 3 minutes (or when finished). The winning team is the one with most correct words.
Variant 2: The students work in teams as before, but the teacher has already written the words on the board (for example vocabulary from yesterday's lesson). The teacher shouts a definition, and the students race to the board to cross out the word defined. Winning team has the most correct 'crosses'.
Running / Shouting Dictations
Running Dictations: Put the text to be dictated on a little sheet of paper, and stick this somewhere far from the students (but within your sight). Student A sits, with paper and pen. Student B goes to the board, reads the first bit, runs back to their partner and tells them it. Student A writes this down. B goes back to the board for the next bit and so on.
Shouting Dictations: Student A and student B have different texts to dictate to each other. But they stand/sit at opposite sides of the room, so they must speak loudly to hear each other. They'll get louder and louder as they realise that they must speak over the other students. It's good for pronunciation as they must enunciate really clearly. It's not so good for the class next door, so keep the texts short, and maybe warn the teacher, in case they were planning a test.
Arrange yourself ...
This is a good way to rearrange your students. Everyone stands up. You tell the students to order themselves in terms of X and they have to mingle to find out about each other and decide where to sit. For example "arrange yourself in order of birthday - January on the left, December on the right." You could also arrange them by how many hours they slept last night, how much they've eaten today, who has the biggest family ...
More lesson warmers to come when I have time.