Present participle; Past participle - grubbing - grubbed Present - grub - grub - grubs - grub - grub - grub Past - grubbed - grubbed - grubbed - grubbed - grubbed - grubbed Future - will grub - will grub - will grub - will grub - will grub - will grub Present conditional - would grub - would grub - would grub - would grub - would grub - would grub Present Perfect - have grubbed - have grubbed - has grubbed - have grubbed - have grubbed - have grubbed Past Perfect - had grubbed - had grubbed - had grubbed - had grubbed - had grubbed - had grubbed Future Perfect - will have grubbed - will have grubbed - will have grubbed - will have grubbed - will have grubbed - will have grubbed Past conditional - would have grubbed - would have grubbed - would have grubbed - would have grubbed - would have grubbed - would have grubbed Imperative - - - grub - - - - - - - -