Hi Allan,
I just finished the quiz for module 3 and just wanted to make it clear that my answer for the second writing question should be seen as below.
When I checked my answer after quiz, it showed in one line and it didn't show any spaces I put, so please refer to the below as my answer to the second writing question.
Thank you.
______________________________________________________________________________________________________________________________________________________

Firstly, I will write down two example sentences as below.

1. I have taught students for 10 years.
2. I have taught students since 2010.

Then I will provide them with visual example as below.

l---------------------------l
2010                      now

        10 years
l--------------------------l
                             now
(I'm going to circle '2010' and '10 years')

And then I will give them other example sentences related to the real situation. Let's say I studied with my students for three months. I could make example sentences as below.

1. We have studied together for three months.
2. We have studied together since November 2020.

With those example sentences, I can explain further that we use 'for' with specific figures, like for three days, for five years, etc, but we use 'since' when we want to mention specific starting point.

When writing those sentences, I will emphasize 'for + ____ ' and ' since + ______' by underlining.

After explaining and practicing, I would like to give them some time to think about their own examples, monitor them walking around the classroom, and then have some students present their own examples.