English verb conjugation
COULD DUCK

Regular verb: duck - ducked - ducked

Affirmation

Simple form	V-ing form
I could duck you could duck she could duck we could duck you could duck they could duck	I could be ducking you could be ducking she could be ducking we could be ducking you could be ducking they could be ducking
Perfect	V-ing perfect
I could have ducked you could have ducked she could have ducked we could have ducked you could have ducked they could have ducked	I could have been ducking you could have been ducking she could have been ducking we could have been ducking you could have been ducking they could have been ducking

Negation

Simple form	V-ing form
I couldn't duck you couldn't duck she couldn't duck we couldn't duck you couldn't duck they couldn't duck	I couldn't be ducking you couldn't be ducking she couldn't be ducking we couldn't be ducking you couldn't be ducking they couldn't be ducking
Perfect	V-ing perfect
I couldn't have ducked you couldn't have ducked she couldn't have ducked we couldn't have ducked you couldn't have ducked they couldn't have ducked	I couldn't have been ducking you couldn't have been ducking she couldn't have been ducking we couldn't have been ducking you couldn't have been ducking they couldn't have been ducking

Interrogative form

Simple form	V-ing form
could I duck? could you duck? could she duck? could we duck? could you duck? could they duck?	could I be ducking? could you be ducking? could she be ducking? could we be ducking? could you be ducking? could they be ducking?
Perfect	V-ing perfect
could I have ducked? could you have ducked? could she have ducked? could we have ducked? could you have ducked? could they have ducked?	could I have been ducking? could you have been ducking? could she have been ducking? could we have been ducking? could you have been ducking? could they have been ducking?

Interro-negative form

Simple form	V-ing form
couldn't I duck? couldn't you duck? couldn't she duck? couldn't we duck? couldn't you duck? couldn't they duck?	couldn't I be ducking? couldn't you be ducking? couldn't she be ducking? couldn't we be ducking? couldn't you be ducking? couldn't they be ducking?
Perfect	V-ing perfect
couldn't I have ducked? couldn't you have ducked? couldn't she have ducked? couldn't we have ducked? couldn't you have ducked? couldn't they have ducked?	couldn't I have been ducking? couldn't you have been ducking? couldn't she have been ducking? couldn't we have been ducking? couldn't you have been ducking? couldn't they have been ducking?