Present participle; Past participle - cracking - cracked Present - crack - crack - cracks - crack - crack - crack Past - cracked - cracked - cracked - cracked - cracked - cracked Future - will crack - will crack - will crack - will crack - will crack - will crack Present conditional - would crack - would crack - would crack - would crack - would crack - would crack Present Perfect - have cracked - have cracked - has cracked - have cracked - have cracked - have cracked Past Perfect - had cracked - had cracked - had cracked - had cracked - had cracked - had cracked Future Perfect - will have cracked - will have cracked - will have cracked - will have cracked - will have cracked - will have cracked Past conditional - would have cracked - would have cracked - would have cracked - would have cracked - would have cracked - would have cracked Imperative - - - crack - - - - - - - -