Teaching the past simple is rather straightforward after you've taught the present simple. Students will be familiar with the idea of auxiliary verbs in the question and negative, but not in the positive form. They'll also be happy to know that the verb conjugation always remains the same. Of course, there's the issue of irregular verbs that can be frustrating. The key to teaching the past simple effectively is making it clear from the beginning that the past simple is used when something begins and ends in the past. The use of appropriate past time expressions will help make this clear.
Introducing the Past Simple
Start by Modeling the Past Simple
Begin teaching the past simple by speaking about some of your past experiences. If possible, use a mix of regular and irregular past verbs. Make sure to use time expressions to provide context. It's also a good idea to mix in some other subjects such as 'my friend' or 'my wife', etc. to signal that there is no change in the conjugation of the past simple other than putting the verb into the past.
I visited my parents in Olympia last weekend.
My wife cooked a wonderful dinner yesterday.
We went to a movie yesterday evening.
Continue modeling by asking yourself a question and providing the answer.
Where did you go last week? - I went to Portland yesterday.
When did you have lunch yesterday? - I had lunch at one o'clock yesterday.
Which level did you teach last month? - I taught beginner and intermediate level classes.
Next ask students similar questions. It's a good idea to use the same verbs - for example: went, had, played, watched, ate - when asking questions. Students will be able to follow your lead and answer appropriately.
Introduce Regular and Irregular Verbs
Using the verbs you've introduced, quickly ask students the infinitive form for each verb. (i.e. "Which verb is went? - go, Which verb is had? - have, etc."). Ask students if the notice any patterns, usually a few students will recognize that many past verbs in '-ed'. Introduce the idea that some verbs are irregular and must be learned. It's a good idea to provide an irregular verb sheet for future reference. Quick drills, such as a past simple grammar chant will help students learn irregular forms.
Finally, introduce the negative form of the past simple through modeling. Model the form to the students and immediately encourage a similar answer. You can do this by asking a student a question, then model a negative and a positive sentence.
When did you have dinner yesterday? - (student) I had dinner at seven o'clock.
Did he have dinner at eight o'clock? - No, he didn't have dinner at eight o'clock. He had dinner at seven o'clock.
Practicing the Past Simple
Explaining the Past Simple on the Board
Use a past tense timeline to visualize the idea that the past simple is used to express something that began and ended in the past. Review time expressions that are used in the past including last week / month / year, in + dates, yesterday.
Once students are familiar with the form, continue expanding their understanding of the form, as well as irregular verbs with comprehension activities. Using stories of vacations, listening descriptions of what happened, or reading news stories will help underline the idea that the past simple is used to narrate what happened in the past.
Continued Activity Practice
Another challenge for students will be understanding the pronunciation of the past forms of regular verbs. Explaining the idea of voiced and voiceless pronunciation patterns will help students understand this pronunciation pattern.