Present participle; Past participle - dulling - dulled Present - dull - dull - dulls - dull - dull - dull Past - dulled - dulled - dulled - dulled - dulled - dulled Future - will dull - will dull - will dull - will dull - will dull - will dull Present conditional - would dull - would dull - would dull - would dull - would dull - would dull Present Perfect - have dulled - have dulled - has dulled - have dulled - have dulled - have dulled Past Perfect - had dulled - had dulled - had dulled - had dulled - had dulled - had dulled Future Perfect - will have dulled - will have dulled - will have dulled - will have dulled - will have dulled - will have dulled Past conditional - would have dulled - would have dulled - would have dulled - would have dulled - would have dulled - would have dulled Imperative - - - dull - - - - - - - -