I could model you could model he could model we could model you could model they could model
V-ing form
I could be modelling you could be modelling he could be modelling we could be modelling you could be modelling they could be modelling
Perfect
I could have modelled you could have modelled he could have modelled we could have modelled you could have modelled they could have modelled
V-ing perfect
I could have been modelling you could have been modelling he could have been modelling we could have been modelling you could have been modelling they could have been modelling
Negation
Simple form
I couldn't model you couldn't model he couldn't model we couldn't model you couldn't model they couldn't model
V-ing form
I couldn't be modelling you couldn't be modelling he couldn't be modelling we couldn't be modelling you couldn't be modelling they couldn't be modelling
Perfect
I couldn't have modelled you couldn't have modelled he couldn't have modelled we couldn't have modelled you couldn't have modelled they couldn't have modelled
V-ing perfect
I couldn't have been modelling you couldn't have been modelling he couldn't have been modelling we couldn't have been modelling you couldn't have been modelling they couldn't have been modelling
Interrogative form
Simple form
could I model? could you model? could he model? could we model? could you model? could they model?
V-ing form
could I be modelling? could you be modelling? could he be modelling? could we be modelling? could you be modelling? could they be modelling?
Perfect
could I have modelled? could you have modelled? could he have modelled? could we have modelled? could you have modelled? could they have modelled?
V-ing perfect
could I have been modelling? could you have been modelling? could he have been modelling? could we have been modelling? could you have been modelling? could they have been modelling?
Interro-negative form
Simple form
couldn't I model? couldn't you model? couldn't he model? couldn't we model? couldn't you model? couldn't they model?
V-ing form
couldn't I be modelling? couldn't you be modelling? couldn't he be modelling? couldn't we be modelling? couldn't you be modelling? couldn't they be modelling?
Perfect
couldn't I have modelled? couldn't you have modelled? couldn't he have modelled? couldn't we have modelled? couldn't you have modelled? couldn't they have modelled?
V-ing perfect
couldn't I have been modelling? couldn't you have been modelling? couldn't he have been modelling? couldn't we have been modelling? couldn't you have been modelling? couldn't they have been modelling?