cograts on your promotion....or congrats for your promotion

Several readers have written to ask which preposition should be used with congratulations. Should we say “congratulations on” or “congratulations for”? The answer is, “It depends.” In the singular, congratulation is the action of congratulating. In the plural, congratulations is what one offers to express pleasure in the success or good fortune of another. The preposition "on" is used when expressing one’s good wishes in the context of a happy event: Congratulations on your marriage! Congratulations on your new baby! Congratulations on your promotion! Congratulations on winning the lottery! Congratulations can be offered as praise for someone’s achievement. In that context, the preposition to use is "for": Congratulations for completing 100 days without an accident! Congratulations for leading the Scouts to safety! Congratulations for saving the farm from foreclosure! Congratulations can also be offered "to" someone. The CEO offered congratulations to all her employees. The townspeople offered congratulations to the utility company for the swift restoration of power.