Present participle; Past participle - co-operating - co-operated Present - co-operate - co-operate - co-operates - co-operate - co-operate - co-operate Past - co-operated - co-operated - co-operated - co-operated - co-operated - co-operated Future - will co-operate - will co-operate - will co-operate - will co-operate - will co-operate - will co-operate Present conditional - would co-operate - would co-operate - would co-operate - would co-operate - would co-operate - would co-operate Present Perfect - have co-operated - have co-operated - has co-operated - have co-operated - have co-operated - have co-operated Past Perfect - had co-operated - had co-operated - had co-operated - had co-operated - had co-operated - had co-operated Future Perfect - will have co-operated - will have co-operated - will have co-operated - will have co-operated - will have co-operated - will have co-operated Past conditional - would have co-operated - would have co-operated - would have co-operated - would have co-operated - would have co-operated - would have co-operated Imperative - - - co-operate - - - - - - - -