story: Pam's kids were in school. She had gone shopping. Pam was still in town when the kids got off of school. Pam asked her sister to pick the kids up. Pam's sister watched the kids until she got home.
 selected sentence: Pam's sister watched the kids until she got home.
Pam's sister want(s) to make sure the kids are safe >Motivates> Pam's sister watches the kids