Lesson 1: Using Preterite or Imperfect, Part 1

http://www.youtube.com/watch?v=Y3O36Eh4cg4

Lesson 2: Using Preterite or Imperfect, Part 2

http://www.youtube.com/watch?v=UOAaNKVSWFs

Lesson 3: Using Preterite or Imperfect, Part 3

http://www.youtube.com/watch?v=yOV1SYlssgA