Present participle; Past participle - complaining - complained Present - complain - complain - complains - complain - complain - complain Past - complained - complained - complained - complained - complained - complained Future - will complain - will complain - will complain - will complain - will complain - will complain Present conditional - would complain - would complain - would complain - would complain - would complain - would complain Present Perfect - have complained - have complained - has complained - have complained - have complained - have complained Past Perfect - had complained - had complained - had complained - had complained - had complained - had complained Future Perfect - will have complained - will have complained - will have complained - will have complained - will have complained - will have complained Past conditional - would have complained - would have complained - would have complained - would have complained - would have complained - would have complained Imperative - - - complain - - - - - - - -