I can refund you can refund he can refund we can refund you can refund they can refund
V-ing form
I can be refunding you can be refunding he can be refunding we can be refunding you can be refunding they can be refunding
Perfect
I can have refunded you can have refunded he can have refunded we can have refunded you can have refunded they can have refunded
V-ing perfect
I can have been refunding you can have been refunding he can have been refunding we can have been refunding you can have been refunding they can have been refunding
Negation
Simple form
I can't refund you can't refund he can't refund we can't refund you can't refund they can't refund
V-ing form
I can't be refunding you can't be refunding he can't be refunding we can't be refunding you can't be refunding they can't be refunding
Perfect
I can't have refunded you can't have refunded he can't have refunded we can't have refunded you can't have refunded they can't have refunded
V-ing perfect
I can't have been refunding you can't have been refunding he can't have been refunding we can't have been refunding you can't have been refunding they can't have been refunding
Interrogative form
Simple form
can I refund? can you refund? can he refund? can we refund? can you refund? can they refund?
V-ing form
can I be refunding? can you be refunding? can he be refunding? can we be refunding? can you be refunding? can they be refunding?
Perfect
can I have refunded? can you have refunded? can he have refunded? can we have refunded? can you have refunded? can they have refunded?
V-ing perfect
can I have been refunding? can you have been refunding? can he have been refunding? can we have been refunding? can you have been refunding? can they have been refunding?
Interro-negative form
Simple form
can't I refund? can't you refund? can't he refund? can't we refund? can't you refund? can't they refund?
V-ing form
can't I be refunding? can't you be refunding? can't he be refunding? can't we be refunding? can't you be refunding? can't they be refunding?
Perfect
can't I have refunded? can't you have refunded? can't he have refunded? can't we have refunded? can't you have refunded? can't they have refunded?
V-ing perfect
can't I have been refunding? can't you have been refunding? can't he have been refunding? can't we have been refunding? can't you have been refunding? can't they have been refunding?