Present participle; Past participle - quacking - quacked Present - quack - quack - quacks - quack - quack - quack Past - quacked - quacked - quacked - quacked - quacked - quacked Future - will quack - will quack - will quack - will quack - will quack - will quack Present conditional - would quack - would quack - would quack - would quack - would quack - would quack Present Perfect - have quacked - have quacked - has quacked - have quacked - have quacked - have quacked Past Perfect - had quacked - had quacked - had quacked - had quacked - had quacked - had quacked Future Perfect - will have quacked - will have quacked - will have quacked - will have quacked - will have quacked - will have quacked Past conditional - would have quacked - would have quacked - would have quacked - would have quacked - would have quacked - would have quacked Imperative - - - quack - - - - - - - -