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