English verb conjugation
COULD FISH

Regular verb: fish - fished - fished

Affirmation

Simple form	V-ing form
I could fish you could fish he could fish we could fish you could fish they could fish	I could be fishing you could be fishing he could be fishing we could be fishing you could be fishing they could be fishing
Perfect	V-ing perfect
I could have fished you could have fished he could have fished we could have fished you could have fished they could have fished	I could have been fishing you could have been fishing he could have been fishing we could have been fishing you could have been fishing they could have been fishing

Negation

Simple form	V-ing form
I couldn't fish you couldn't fish he couldn't fish we couldn't fish you couldn't fish they couldn't fish	I couldn't be fishing you couldn't be fishing he couldn't be fishing we couldn't be fishing you couldn't be fishing they couldn't be fishing
Perfect	V-ing perfect
I couldn't have fished you couldn't have fished he couldn't have fished we couldn't have fished you couldn't have fished they couldn't have fished	I couldn't have been fishing you couldn't have been fishing he couldn't have been fishing we couldn't have been fishing you couldn't have been fishing they couldn't have been fishing

Interrogative form

Simple form	V-ing form
could I fish? could you fish? could he fish? could we fish? could you fish? could they fish?	could I be fishing? could you be fishing? could he be fishing? could we be fishing? could you be fishing? could they be fishing?
Perfect	V-ing perfect
could I have fished? could you have fished? could he have fished? could we have fished? could you have fished? could they have fished?	could I have been fishing? could you have been fishing? could he have been fishing? could we have been fishing? could you have been fishing? could they have been fishing?

Interro-negative form

Simple form	V-ing form
couldn't I fish? couldn't you fish? couldn't he fish? couldn't we fish? couldn't you fish? couldn't they fish?	couldn't I be fishing? couldn't you be fishing? couldn't he be fishing? couldn't we be fishing? couldn't you be fishing? couldn't they be fishing?
Perfect	V-ing perfect
couldn't I have fished? couldn't you have fished? couldn't he have fished? couldn't we have fished? couldn't you have fished? couldn't they have fished?	couldn't I have been fishing? couldn't you have been fishing? couldn't he have been fishing? couldn't we have been fishing? couldn't you have been fishing? couldn't they have been fishing?