Timelines are a tried and true way to help EFL students conceptualize tense and aspect. The following is an example of how a timeline can be used to help students in the English classroom talk about the past.
Come up with a list of life events. Start with birth, and move into adulthood, e.g. graduating, getting a job, moving, buying a house, having kids, etc. Have pairs interview each other about when these events took place in their own lives. As the partner listens, they should mark the event on a timeline with an X.
If you wish, now would be an opportunity to have the class share the life of their partner. You can also wait to do this until later in the lesson.
Put up your own timeline. Along with the X’s, you should also indicate the time when you were in school or working at a particular job. A bar usually works. Now offer them an example using the past progressive: “I earned my TEFL certificate while I was living in Argentina.”
It’s important that they see A) that these events took place at the same time and B) that one event “interrupted” the other. Remember to highlight the keyword “while,” and demonstrate how the order can be swapped, e.g. “While I was living in Argentina, I earned my TEFL certificate.”
Have partners, the same or new, compare their timelines and come up with examples using the past progressive. “While Maria was working as a lawyer, Manuel bought his first house.”
If students are advanced, see if they can create examples using the past perfect. You can also ask them to give a short presentation about the life of their partner.
Again, this is a great way for EFL students to practice grammar and to learn about each other at the same time. If you have a website for your class, ask students to then write up their partner’s biography and post them online. As you practice more structures the biographies can be updated to include new information.