Teaching grammar to students in a second language is maybe the hardest thing about being an ESL teacher. I've always found that V3 (present perfect) is easy to teach structurally, but hard for students to grasp in terms of its colloquial usage -- we use V3 very often as native English speakers when talking about the past. With this class, we are returning to V3 for the third time, and I'm still working with them to understand how it should be used when speaking. It takes lots of demonstrations and lots of different activities -- and on top of that, they still need to learn new irregular verbs. Here's a video of the class:
