Present participle; Past participle - knocking - knocked Present - knock - knock - knocks - knock - knock - knock Past - knocked - knocked - knocked - knocked - knocked - knocked Future - will knock - will knock - will knock - will knock - will knock - will knock Present conditional - would knock - would knock - would knock - would knock - would knock - would knock Present Perfect - have knocked - have knocked - has knocked - have knocked - have knocked - have knocked Past Perfect - had knocked - had knocked - had knocked - had knocked - had knocked - had knocked Future Perfect - will have knocked - will have knocked - will have knocked - will have knocked - will have knocked - will have knocked Past conditional - would have knocked - would have knocked - would have knocked - would have knocked - would have knocked - would have knocked Imperative - - - knock - - - - - - - -