I can well you can well he can well we can well you can well they can well
V-ing form
I can be welling you can be welling he can be welling we can be welling you can be welling they can be welling
Perfect
I can have welled you can have welled he can have welled we can have welled you can have welled they can have welled
V-ing perfect
I can have been welling you can have been welling he can have been welling we can have been welling you can have been welling they can have been welling
Negation
Simple form
I cannot well you cannot well he cannot well we cannot well you cannot well they cannot well
V-ing form
I cannot be welling you cannot be welling he cannot be welling we cannot be welling you cannot be welling they cannot be welling
Perfect
I cannot have welled you cannot have welled he cannot have welled we cannot have welled you cannot have welled they cannot have welled
V-ing perfect
I cannot have been welling you cannot have been welling he cannot have been welling we cannot have been welling you cannot have been welling they cannot have been welling
Interrogative form
Simple form
can I well? can you well? can he well? can we well? can you well? can they well?
V-ing form
can I be welling? can you be welling? can he be welling? can we be welling? can you be welling? can they be welling?
Perfect
can I have welled? can you have welled? can he have welled? can we have welled? can you have welled? can they have welled?
V-ing perfect
can I have been welling? can you have been welling? can he have been welling? can we have been welling? can you have been welling? can they have been welling?
Interro-negative form
Simple form
can I not well? can you not well? can he not well? can we not well? can you not well? can they not well?
V-ing form
can I not be welling? can you not be welling? can he not be welling? can we not be welling? can you not be welling? can they not be welling?
Perfect
can I not have welled? can you not have welled? can he not have welled? can we not have welled? can you not have welled? can they not have welled?
V-ing perfect
can I not have been welling? can you not have been welling? can he not have been welling? can we not have been welling? can you not have been welling? can they not have been welling?