Present participle; Past participle - buckling - buckled Present - buckle - buckle - buckles - buckle - buckle - buckle Past - buckled - buckled - buckled - buckled - buckled - buckled Future - will buckle - will buckle - will buckle - will buckle - will buckle - will buckle Present conditional - would buckle - would buckle - would buckle - would buckle - would buckle - would buckle Present Perfect - have buckled - have buckled - has buckled - have buckled - have buckled - have buckled Past Perfect - had buckled - had buckled - had buckled - had buckled - had buckled - had buckled Future Perfect - will have buckled - will have buckled - will have buckled - will have buckled - will have buckled - will have buckled Past conditional - would have buckled - would have buckled - would have buckled - would have buckled - would have buckled - would have buckled Imperative - - - buckle - - - - - - - -