Here is a very simple activity to revise vocabulary:
Put the students into two groups. One student from each group comes to the board. Jumble the letters of the words they have recently learnt (e.g. hiessfl –> selfish). Read out letters for them to write on the board. As soon as they or someone from the group knows what the adjective is they complete the word. The first to do so, spelt correctly, wins a point. If they can build a sentence using this word or give a definition, they can get another point.