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 cannot mast you cannot mast he cannot mast we cannot mast you cannot mast they cannot mast
V-ing form
I cannot be masting you cannot be masting he cannot be masting we cannot be masting you cannot be masting they cannot be masting
Perfect
I cannot have masted you cannot have masted he cannot have masted we cannot have masted you cannot have masted they cannot have masted
V-ing perfect
I cannot have been masting you cannot have been masting he cannot have been masting we cannot have been masting you cannot have been masting they cannot 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 I not mast? can you not mast? can he not mast? can we not mast? can you not mast? can they not mast?
V-ing form
can I not be masting? can you not be masting? can he not be masting? can we not be masting? can you not be masting? can they not be masting?
Perfect
can I not have masted? can you not have masted? can he not have masted? can we not have masted? can you not have masted? can they not have masted?
V-ing perfect
can I not have been masting? can you not have been masting? can he not have been masting? can we not have been masting? can you not have been masting? can they not have been masting?