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 couldn't marvel you couldn't marvel he couldn't marvel we couldn't marvel you couldn't marvel they couldn't marvel
V-ing form
I couldn't be marvelling you couldn't be marvelling he couldn't be marvelling we couldn't be marvelling you couldn't be marvelling they couldn't be marvelling
Perfect
I couldn't have marvelled you couldn't have marvelled he couldn't have marvelled we couldn't have marvelled you couldn't have marvelled they couldn't have marvelled
V-ing perfect
I couldn't have been marvelling you couldn't have been marvelling he couldn't have been marvelling we couldn't have been marvelling you couldn't have been marvelling they couldn't 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
couldn't I marvel? couldn't you marvel? couldn't he marvel? couldn't we marvel? couldn't you marvel? couldn't they marvel?
V-ing form
couldn't I be marvelling? couldn't you be marvelling? couldn't he be marvelling? couldn't we be marvelling? couldn't you be marvelling? couldn't they be marvelling?
Perfect
couldn't I have marvelled? couldn't you have marvelled? couldn't he have marvelled? couldn't we have marvelled? couldn't you have marvelled? couldn't they have marvelled?
V-ing perfect
couldn't I have been marvelling? couldn't you have been marvelling? couldn't he have been marvelling? couldn't we have been marvelling? couldn't you have been marvelling? couldn't they have been marvelling?