I can mast you can mast he can mast we can mast you can mast they can mast
V-ing form
I can be masting you can be masting he can be masting we can be masting you can be masting they can be masting
Perfect
I can have masted you can have masted he can have masted we can have masted you can have masted they can have masted
V-ing perfect
I can have been masting you can have been masting he can have been masting we can have been masting you can have been masting they can have been masting
Negation
Simple form
I can't mast you can't mast he can't mast we can't mast you can't mast they can't mast
V-ing form
I can't be masting you can't be masting he can't be masting we can't be masting you can't be masting they can't be masting
Perfect
I can't have masted you can't have masted he can't have masted we can't have masted you can't have masted they can't have masted
V-ing perfect
I can't have been masting you can't have been masting he can't have been masting we can't have been masting you can't have been masting they can't have been masting
Interrogative form
Simple form
can I mast? can you mast? can he mast? can we mast? can you mast? can they mast?
V-ing form
can I be masting? can you be masting? can he be masting? can we be masting? can you be masting? can they be masting?
Perfect
can I have masted? can you have masted? can he have masted? can we have masted? can you have masted? can they have masted?
V-ing perfect
can I have been masting? can you have been masting? can he have been masting? can we have been masting? can you have been masting? can they have been masting?
Interro-negative form
Simple form
can't I mast? can't you mast? can't he mast? can't we mast? can't you mast? can't they mast?
V-ing form
can't I be masting? can't you be masting? can't he be masting? can't we be masting? can't you be masting? can't they be masting?
Perfect
can't I have masted? can't you have masted? can't he have masted? can't we have masted? can't you have masted? can't they have masted?
V-ing perfect
can't I have been masting? can't you have been masting? can't he have been masting? can't we have been masting? can't you have been masting? can't they have been masting?