Challenge your students on the typical mistakes of past simple tense
Although past simple is quite easy in forms, students still make mistakes when they are forming it. Their sentences look somewhat OK to them and quite confident about them.
What does it cover?
One of the most frequent mistakes is forgetting the infinitive forms in negative or question forms. Students easily forget to change the verb form. Also, they put was or were in every sentence regardless of any necessity. Another typical mistake is forgetting the irregular verb form and conjugating it like a proper regular verb.