1. Last night, I was writing wedding invitations while my ex-boyfriend called me. → when

2. We visited the charity, talking to their manager and gave them the donations. → talked

3. To recording your voice, you can download a mobile application. → record

4. He putted on a thick coat and went out in the snowstorm to find his dog. → put

5. Half of the school's students are not used to follow the new winter rules. → following