I have a problem in how to present a 15-minute lesson plan for introducing simple past. I am in a teachers course and I was asked to design a lesson in wich grammar is covert. My objective is to introduce affirmative sentences using regular and irregular verbs. My idea is to use Robin Hood for setting a context. I´m going to show some visuals: the first visual is Robin Hood, the second is a forest, the third is Robin Hood hunting, the fourth is Robin helping people, the fifth is a robber, the sixth are spears and the seventh is Robin hood riding a horse. I need to introduce four regular verbs and two irrregular. (Live, hunt, help, rob, fight and ride) At the beginning I will introduce Robin Hood. Then I will show students the verbs I mentioned but in their infinitive form. Students will match the verbs to the visuals by sticking them below each visual. After that, I will start to tell the story and introduce a first sentence in past (orally and in written form). E.g. "This is Robin Hood. He lived in a forest" then I will try to elicit the rest of the verbs and let students to make the mistake with irregular verbs. The reason is to make them noticed irregular verbs have different pronunciation and spelling in past. After that, I will write some gap sentences students will fill in. Volunteers pass to the board. Everybody checks. This is the end of the introductory lesson.
I don´t feel enough convinced with this lesson. What do you think? Can suggest me another idea(s)for teaching covert grammar?