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