Present participle; Past participle - referring - referred Present - refer - refer - refers - refer - refer - refer Past - referred - referred - referred - referred - referred - referred Future - will refer - will refer - will refer - will refer - will refer - will refer Present conditional - would refer - would refer - would refer - would refer - would refer - would refer Present Perfect - have referred - have referred - has referred - have referred - have referred - have referred Past Perfect - had referred - had referred - had referred - had referred - had referred - had referred Future Perfect - will have referred - will have referred - will have referred - will have referred - will have referred - will have referred Past conditional - would have referred - would have referred - would have referred - would have referred - would have referred - would have referred Imperative - - - refer - - - - - - - -