There is no better way - or at least more common way - to start a new school year than by revising the tenses we believe our students already know. Since I decided to take it easy on them I prepared a very easy listening activity. Students simply listen to Katy Perry's latest hit and fill the gaps with the correct form of the verbs in brackets. You can discuss the choice or use of tenses afterwards. There is also a short listening comprehension exercise. All you have to do is download the song or simply use Katy's official video on YouTube. Hope your students will enjoy it.