oi vs wo

oi

• An expression of surprise. 

• An informal greeting, similar to hi. 

• Said to get someone's attention; hey. 

• I. 

• A working-class punk rock subgenre of the 1970s, sometimes associated with racism. 

wo

• A call to cause a horse to slow down or stop; whoa. 

• A falconer's call to a hawk. 

• A wall.