Latin Prefix "co-"
* cooperate: to work together
* coexist: to exist together
* coauthor: to write together
* coworker: a person who works together with another
* coeducational: involving both male and female students
* cohesion: the act or state of sticking together
* cohabitation: living together as a couple
* cognizant: being aware of something
Latin Prefix "com-"
* combine: to join together
* communicate: to share information
* commemorate: to remember or celebrate something
* compassionate: feeling or showing sympathy
* comprehensive: including everything
* compromise: an agreement reached by making concessions
* companion: a person who accompanies another
* congregate: to gather together
Greek Prefix "syn-"
* synchronize: to cause to happen at the same time
* synthesis: the combination of parts to make a whole
* synergy: the combined effect of two things that is greater than the sum of their individual effects
* sympathy: feelings of pity and sorrow for someone else
* symphony: a musical composition for a large orchestra
Other Prefixes
* collaborate: to work together
* coalesce: to come together and form one mass
* concur: to agree
* concurrent: happening at the same time
* consolidate: to combine into a single unit
* conviviality: the quality of being festive and sociable
This is not an exhaustive list, but it gives you a good starting point. Remember that some prefixes can have multiple meanings, so it's always best to check the dictionary if you're unsure about the meaning of a particular word.