Present participle; Past participle - sapping - sapped Present - sap - sap - saps - sap - sap - sap Past - sapped - sapped - sapped - sapped - sapped - sapped Future - will sap - will sap - will sap - will sap - will sap - will sap Present conditional - would sap - would sap - would sap - would sap - would sap - would sap Present Perfect - have sapped - have sapped - has sapped - have sapped - have sapped - have sapped Past Perfect - had sapped - had sapped - had sapped - had sapped - had sapped - had sapped Future Perfect - will have sapped - will have sapped - will have sapped - will have sapped - will have sapped - will have sapped Past conditional - would have sapped - would have sapped - would have sapped - would have sapped - would have sapped - would have sapped Imperative - - - sap - - - - - - - -