Little differences can make huge changes in the meaning when used incorrectly. One needs to be really cautious.

Depreciate and Deprecate have the difference of single ‘i’ only.

Depreciate means to belittle or undervalue something/someone
The market value of my shares has depreciated by five percent.
Never depreciate the value of parents and teachers.

Deprecate means to express one’s disapproval of something
Anna Hazare deprecated the selfish and secular motives of our political leaders.
The principal deprecated any form of cheating during examinations.