Present participle; Past participle - preventing - prevented Present - prevent - prevent - prevents - prevent - prevent - prevent Past - prevented - prevented - prevented - prevented - prevented - prevented Future - will prevent - will prevent - will prevent - will prevent - will prevent - will prevent Present conditional - would prevent - would prevent - would prevent - would prevent - would prevent - would prevent Present Perfect - have prevented - have prevented - has prevented - have prevented - have prevented - have prevented Past Perfect - had prevented - had prevented - had prevented - had prevented - had prevented - had prevented Future Perfect - will have prevented - will have prevented - will have prevented - will have prevented - will have prevented - will have prevented Past conditional - would have prevented - would have prevented - would have prevented - would have prevented - would have prevented - would have prevented Imperative - - - prevent - - - - - - - -