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