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