I could grow you could grow she could grow we could grow you could grow they could grow
V-ing form
I could be growing you could be growing she could be growing we could be growing you could be growing they could be growing
Perfect
I could have grown you could have grown she could have grown we could have grown you could have grown they could have grown
V-ing perfect
I could have been growing you could have been growing she could have been growing we could have been growing you could have been growing they could have been growing
Negation
Simple form
I couldn't grow you couldn't grow she couldn't grow we couldn't grow you couldn't grow they couldn't grow
V-ing form
I couldn't be growing you couldn't be growing she couldn't be growing we couldn't be growing you couldn't be growing they couldn't be growing
Perfect
I couldn't have grown you couldn't have grown she couldn't have grown we couldn't have grown you couldn't have grown they couldn't have grown
V-ing perfect
I couldn't have been growing you couldn't have been growing she couldn't have been growing we couldn't have been growing you couldn't have been growing they couldn't have been growing
Interrogative form
Simple form
could I grow? could you grow? could she grow? could we grow? could you grow? could they grow?
V-ing form
could I be growing? could you be growing? could she be growing? could we be growing? could you be growing? could they be growing?
Perfect
could I have grown? could you have grown? could she have grown? could we have grown? could you have grown? could they have grown?
V-ing perfect
could I have been growing? could you have been growing? could she have been growing? could we have been growing? could you have been growing? could they have been growing?
Interro-negative form
Simple form
couldn't I grow? couldn't you grow? couldn't she grow? couldn't we grow? couldn't you grow? couldn't they grow?
V-ing form
couldn't I be growing? couldn't you be growing? couldn't she be growing? couldn't we be growing? couldn't you be growing? couldn't they be growing?
Perfect
couldn't I have grown? couldn't you have grown? couldn't she have grown? couldn't we have grown? couldn't you have grown? couldn't they have grown?
V-ing perfect
couldn't I have been growing? couldn't you have been growing? couldn't she have been growing? couldn't we have been growing? couldn't you have been growing? couldn't they have been growing?