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