Regular verb: refer - referred - referred
Simple form | V-ing form |
I must refer you must refer he must refer we must refer you must refer they must refer | I must be referring you must be referring he must be referring we must be referring you must be referring they must be referring |
Perfect | V-ing perfect |
I must have referred you must have referred he must have referred we must have referred you must have referred they must have referred | I must have been referring you must have been referring he must have been referring we must have been referring you must have been referring they must have been referring |
Simple form | V-ing form |
I mustn't refer you mustn't refer he mustn't refer we mustn't refer you mustn't refer they mustn't refer | I mustn't be referring you mustn't be referring he mustn't be referring we mustn't be referring you mustn't be referring they mustn't be referring |
Perfect | V-ing perfect |
I mustn't have referred you mustn't have referred he mustn't have referred we mustn't have referred you mustn't have referred they mustn't have referred | I mustn't have been referring you mustn't have been referring he mustn't have been referring we mustn't have been referring you mustn't have been referring they mustn't have been referring |
Simple form | V-ing form |
must I refer? must you refer? must he refer? must we refer? must you refer? must they refer? | must I be referring? must you be referring? must he be referring? must we be referring? must you be referring? must they be referring? |
Perfect | V-ing perfect |
must I have referred? must you have referred? must he have referred? must we have referred? must you have referred? must they have referred? | must I have been referring? must you have been referring? must he have been referring? must we have been referring? must you have been referring? must they have been referring? |
Simple form | V-ing form |
mustn't I refer? mustn't you refer? mustn't he refer? mustn't we refer? mustn't you refer? mustn't they refer? | mustn't I be referring? mustn't you be referring? mustn't he be referring? mustn't we be referring? mustn't you be referring? mustn't they be referring? |
Perfect | V-ing perfect |
mustn't I have referred? mustn't you have referred? mustn't he have referred? mustn't we have referred? mustn't you have referred? mustn't they have referred? | mustn't I have been referring? mustn't you have been referring? mustn't he have been referring? mustn't we have been referring? mustn't you have been referring? mustn't they have been referring? |