Answer
An example of a monoprotic acid would be HCl (hydrochloric acid). An example of a diprotic acid would be H$_2$CO$_3$ (carbonic acid). An example of a triprotic acid would be H$_3$PO$_4$ (phosphoric acid).
Work Step by Step
A monoprotic acid deprotonates only one proton, a diprotic acid deprotonates two protons (in two separate reactions) and a triprotic acid deprotonates three protons (in three separate reactions).
Note: Deprotonate means to donate a proton.