English verb conjugation
CAN FISH

Regular verb: fish - fished - fished

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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