Stem Changing Verbs

STEM CHANGES:
- the "e"changes to "ie"
- the "o" changes to "ue"
- the "e" changes to "i" and sometimes "u" to "ue"
Changes occur in all forms except nosotros because:
WE ARE SPECIAL! It is challenging! (Refer to p. 399 and 401 for help, if needed.)
See if you can find the correct conjugation for these common verbs.