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