Present participle; Past participle - scumming - scummed Present - scum - scum - scums - scum - scum - scum Past - scummed - scummed - scummed - scummed - scummed - scummed Future - will scum - will scum - will scum - will scum - will scum - will scum Present conditional - would scum - would scum - would scum - would scum - would scum - would scum Present Perfect - have scummed - have scummed - has scummed - have scummed - have scummed - have scummed Past Perfect - had scummed - had scummed - had scummed - had scummed - had scummed - had scummed Future Perfect - will have scummed - will have scummed - will have scummed - will have scummed - will have scummed - will have scummed Past conditional - would have scummed - would have scummed - would have scummed - would have scummed - would have scummed - would have scummed Imperative - - - scum - - - - - - - -