I use this cut-up worksheet to revise the present simple. There is a mistake in every sentence, which students have to correct. It works extremely well as a pairwork activity: students have to discuss and give their reasons about why something is wrong.
As an alternative, you can change the worksheet and correct one or two sentences. Then make students not only correct the wrong sentences but also find out which are the correct sentences.
The worksheet's got two pages with the key on the second page. If you use duplex printing, students can check themselves on the back of their sheets.