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