I could marvel you could marvel he could marvel we could marvel you could marvel they could marvel
V-ing form
I could be marvelling you could be marvelling he could be marvelling we could be marvelling you could be marvelling they could be marvelling
Perfect
I could have marvelled you could have marvelled he could have marvelled we could have marvelled you could have marvelled they could have marvelled
V-ing perfect
I could have been marvelling you could have been marvelling he could have been marvelling we could have been marvelling you could have been marvelling they could have been marvelling
Negation
Simple form
I could not marvel you could not marvel he could not marvel we could not marvel you could not marvel they could not marvel
V-ing form
I could not be marvelling you could not be marvelling he could not be marvelling we could not be marvelling you could not be marvelling they could not be marvelling
Perfect
I could not have marvelled you could not have marvelled he could not have marvelled we could not have marvelled you could not have marvelled they could not have marvelled
V-ing perfect
I could not have been marvelling you could not have been marvelling he could not have been marvelling we could not have been marvelling you could not have been marvelling they could not have been marvelling
Interrogative form
Simple form
could I marvel? could you marvel? could he marvel? could we marvel? could you marvel? could they marvel?
V-ing form
could I be marvelling? could you be marvelling? could he be marvelling? could we be marvelling? could you be marvelling? could they be marvelling?
Perfect
could I have marvelled? could you have marvelled? could he have marvelled? could we have marvelled? could you have marvelled? could they have marvelled?
V-ing perfect
could I have been marvelling? could you have been marvelling? could he have been marvelling? could we have been marvelling? could you have been marvelling? could they have been marvelling?
Interro-negative form
Simple form
could I not marvel? could you not marvel? could he not marvel? could we not marvel? could you not marvel? could they not marvel?
V-ing form
could I not be marvelling? could you not be marvelling? could he not be marvelling? could we not be marvelling? could you not be marvelling? could they not be marvelling?
Perfect
could I not have marvelled? could you not have marvelled? could he not have marvelled? could we not have marvelled? could you not have marvelled? could they not have marvelled?
V-ing perfect
could I not have been marvelling? could you not have been marvelling? could he not have been marvelling? could we not have been marvelling? could you not have been marvelling? could they not have been marvelling?