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