Ответ:

  1. Last summer Dan visited his Granny in the country.
  2. Nick and Tom went to a summer camp in June.
  3. Ann spent her holidays in the city.
  4. She and her friends went roller-skating in the park.
  5. My friends me on a hike last summer.
  6. I sang songs with my friends by the campfire.

В утвердительных предложениях в Past Simple у правильных глаголов добавляется окончание -ed, а неправильные глаголы имеют особые формы: go — went, spend — spent, take — took, sing — sang.