12. To do, do, did, doing
13. To come, come, came, coming
14. To help, help, helped, helping
15. To fix, fix, fixed, fixing
16. To call, call, called, calling
17. To mix, mix, mixed, mixing
18. To tell, tell, told, telling
19. To look, look, looked, looking
20. To describe, describe, described, describing
21. To write, write, wrote, writing