I could smell you could smell she could smell we could smell you could smell they could smell
V-ing form
I could be smelling you could be smelling she could be smelling we could be smelling you could be smelling they could be smelling
Perfect
I could have smelled, smelt you could have smelled, smelt she could have smelled, smelt we could have smelled, smelt you could have smelled, smelt they could have smelled, smelt
V-ing perfect
I could have been smelling you could have been smelling she could have been smelling we could have been smelling you could have been smelling they could have been smelling
Negation
Simple form
I could not smell you could not smell she could not smell we could not smell you could not smell they could not smell
V-ing form
I could not be smelling you could not be smelling she could not be smelling we could not be smelling you could not be smelling they could not be smelling
Perfect
I could not have smelled, smelt you could not have smelled, smelt she could not have smelled, smelt we could not have smelled, smelt you could not have smelled, smelt they could not have smelled, smelt
V-ing perfect
I could not have been smelling you could not have been smelling she could not have been smelling we could not have been smelling you could not have been smelling they could not have been smelling
Interrogative form
Simple form
could I smell? could you smell? could she smell? could we smell? could you smell? could they smell?
V-ing form
could I be smelling? could you be smelling? could she be smelling? could we be smelling? could you be smelling? could they be smelling?
Perfect
could I have smelled, smelt? could you have smelled, smelt? could she have smelled, smelt? could we have smelled, smelt? could you have smelled, smelt? could they have smelled, smelt?
V-ing perfect
could I have been smelling? could you have been smelling? could she have been smelling? could we have been smelling? could you have been smelling? could they have been smelling?
Interro-negative form
Simple form
could I not smell? could you not smell? could she not smell? could we not smell? could you not smell? could they not smell?
V-ing form
could I not be smelling? could you not be smelling? could she not be smelling? could we not be smelling? could you not be smelling? could they not be smelling?
Perfect
could I not have smelled, smelt? could you not have smelled, smelt? could she not have smelled, smelt? could we not have smelled, smelt? could you not have smelled, smelt? could they not have smelled, smelt?
V-ing perfect
could I not have been smelling? could you not have been smelling? could she not have been smelling? could we not have been smelling? could you not have been smelling? could they not have been smelling?