Sarah: Hi, Jim. What’s your plan for this weekend?

James: Well, some of my classmates and I are going on a hike. I was wondering if you were free to join us.

Sarah: Wow! That sounds a lot of fun.. Next weekend my brother is coming to see me and I’ve got to be a tour guide and show him around the city. Would you be interested in going with us?

James: I’d love to, but Joan and I have already planned to go skiing in the mountains.

Sarah: Mmm, I envy you—but I can’t ski.