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