Present participle; Past participle - knowing - known Present - know - know - knows - know - know - know Past - knew - knew - knew - knew - knew - knew Future - will know - will know - will know - will know - will know - will know Present conditional - would know - would know - would know - would know - would know - would know Present Perfect - have known - have known - has known - have known - have known - have known Past Perfect - had known - had known - had known - had known - had known - had known Future Perfect - will have known - will have known - will have known - will have known - will have known - will have known Past conditional - would have known - would have known - would have known - would have known - would have known - would have known Imperative - - - know - - - - - - - -