Present participle; Past participle - souring - soured Present - sour - sour - sours - sour - sour - sour Past - soured - soured - soured - soured - soured - soured Future - will sour - will sour - will sour - will sour - will sour - will sour Present conditional - would sour - would sour - would sour - would sour - would sour - would sour Present Perfect - have soured - have soured - has soured - have soured - have soured - have soured Past Perfect - had soured - had soured - had soured - had soured - had soured - had soured Future Perfect - will have soured - will have soured - will have soured - will have soured - will have soured - will have soured Past conditional - would have soured - would have soured - would have soured - would have soured - would have soured - would have soured Imperative - - - sour - - - - - - - -