Symptoms
Is it possible to have a workflow use multiple words such as "Approve" and "Approved" to action a task through email?
Diagnoses
It is possible to configure synonyms for process actions.
Resolution
SmartActions synonyms can be configured in the K2HostServer.exe.config file. Please see the following documentation for more details:
http://help.k2.com/onlinehelp/K2blackpearl/ICG/4.6.8/webframe.html_K2_SmartActions_K2_Server_Configuration.html
It is the best idea to make a backup copy of this file before making any changes, and after making changes you will need to restart the K2 service before they will take effect..