I can fishtail you can fishtail she can fishtail we can fishtail you can fishtail they can fishtail
V-ing form
I can be fishtailing you can be fishtailing she can be fishtailing we can be fishtailing you can be fishtailing they can be fishtailing
Perfect
I can have fishtailed you can have fishtailed she can have fishtailed we can have fishtailed you can have fishtailed they can have fishtailed
V-ing perfect
I can have been fishtailing you can have been fishtailing she can have been fishtailing we can have been fishtailing you can have been fishtailing they can have been fishtailing
Negation
Simple form
I can't fishtail you can't fishtail she can't fishtail we can't fishtail you can't fishtail they can't fishtail
V-ing form
I can't be fishtailing you can't be fishtailing she can't be fishtailing we can't be fishtailing you can't be fishtailing they can't be fishtailing
Perfect
I can't have fishtailed you can't have fishtailed she can't have fishtailed we can't have fishtailed you can't have fishtailed they can't have fishtailed
V-ing perfect
I can't have been fishtailing you can't have been fishtailing she can't have been fishtailing we can't have been fishtailing you can't have been fishtailing they can't have been fishtailing
Interrogative form
Simple form
can I fishtail? can you fishtail? can she fishtail? can we fishtail? can you fishtail? can they fishtail?
V-ing form
can I be fishtailing? can you be fishtailing? can she be fishtailing? can we be fishtailing? can you be fishtailing? can they be fishtailing?
Perfect
can I have fishtailed? can you have fishtailed? can she have fishtailed? can we have fishtailed? can you have fishtailed? can they have fishtailed?
V-ing perfect
can I have been fishtailing? can you have been fishtailing? can she have been fishtailing? can we have been fishtailing? can you have been fishtailing? can they have been fishtailing?
Interro-negative form
Simple form
can't I fishtail? can't you fishtail? can't she fishtail? can't we fishtail? can't you fishtail? can't they fishtail?
V-ing form
can't I be fishtailing? can't you be fishtailing? can't she be fishtailing? can't we be fishtailing? can't you be fishtailing? can't they be fishtailing?
Perfect
can't I have fishtailed? can't you have fishtailed? can't she have fishtailed? can't we have fishtailed? can't you have fishtailed? can't they have fishtailed?
V-ing perfect
can't I have been fishtailing? can't you have been fishtailing? can't she have been fishtailing? can't we have been fishtailing? can't you have been fishtailing? can't they have been fishtailing?