Present participle; Past participle - troubling - troubled Present - trouble - trouble - troubles - trouble - trouble - trouble Past - troubled - troubled - troubled - troubled - troubled - troubled Future - will trouble - will trouble - will trouble - will trouble - will trouble - will trouble Present conditional - would trouble - would trouble - would trouble - would trouble - would trouble - would trouble Present Perfect - have troubled - have troubled - has troubled - have troubled - have troubled - have troubled Past Perfect - had troubled - had troubled - had troubled - had troubled - had troubled - had troubled Future Perfect - will have troubled - will have troubled - will have troubled - will have troubled - will have troubled - will have troubled Past conditional - would have troubled - would have troubled - would have troubled - would have troubled - would have troubled - would have troubled Imperative - - - trouble - - - - - - - -