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