Present participle; Past participle - failing - failed Present - fail - fail - fails - fail - fail - fail Past - failed - failed - failed - failed - failed - failed Future - will fail - will fail - will fail - will fail - will fail - will fail Present conditional - would fail - would fail - would fail - would fail - would fail - would fail Present Perfect - have failed - have failed - has failed - have failed - have failed - have failed Past Perfect - had failed - had failed - had failed - had failed - had failed - had failed Future Perfect - will have failed - will have failed - will have failed - will have failed - will have failed - will have failed Past conditional - would have failed - would have failed - would have failed - would have failed - would have failed - would have failed Imperative - - - fail - - - - - - - -