Present participle; Past participle - brightening - brightened Present - brighten - brighten - brightens - brighten - brighten - brighten Past - brightened - brightened - brightened - brightened - brightened - brightened Future - will brighten - will brighten - will brighten - will brighten - will brighten - will brighten Present conditional - would brighten - would brighten - would brighten - would brighten - would brighten - would brighten Present Perfect - have brightened - have brightened - has brightened - have brightened - have brightened - have brightened Past Perfect - had brightened - had brightened - had brightened - had brightened - had brightened - had brightened Future Perfect - will have brightened - will have brightened - will have brightened - will have brightened - will have brightened - will have brightened Past conditional - would have brightened - would have brightened - would have brightened - would have brightened - would have brightened - would have brightened Imperative - - - brighten - - - - - - - -