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