Pasado participio.

                Base          Past           Past
               Form.         tense.       participle.   

1.  S     work      worked      worked
2. D     see         saw             seen
3. S     have        has             had
4. D    visit         visited         visited
5. D      be        was/were     been
6. S     wait       waited         waited
7. S     leave       left             left
8. D     take       took           taken
9. S     know     knew          know
10.D    eat         ate             eaten