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