I can fishtail you can fishtail he can fishtail we can fishtail you can fishtail they can fishtail
V-ing form
I can be fishtailing you can be fishtailing he can be fishtailing we can be fishtailing you can be fishtailing they can be fishtailing
Perfect
I can have fishtailed you can have fishtailed he 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 he can have been fishtailing we can have been fishtailing you can have been fishtailing they can have been fishtailing
Negation
Simple form
I cannot fishtail you cannot fishtail he cannot fishtail we cannot fishtail you cannot fishtail they cannot fishtail
V-ing form
I cannot be fishtailing you cannot be fishtailing he cannot be fishtailing we cannot be fishtailing you cannot be fishtailing they cannot be fishtailing
Perfect
I cannot have fishtailed you cannot have fishtailed he cannot have fishtailed we cannot have fishtailed you cannot have fishtailed they cannot have fishtailed
V-ing perfect
I cannot have been fishtailing you cannot have been fishtailing he cannot have been fishtailing we cannot have been fishtailing you cannot have been fishtailing they cannot have been fishtailing
Interrogative form
Simple form
can I fishtail? can you fishtail? can he fishtail? can we fishtail? can you fishtail? can they fishtail?
V-ing form
can I be fishtailing? can you be fishtailing? can he be fishtailing? can we be fishtailing? can you be fishtailing? can they be fishtailing?
Perfect
can I have fishtailed? can you have fishtailed? can he 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 he have been fishtailing? can we have been fishtailing? can you have been fishtailing? can they have been fishtailing?
Interro-negative form
Simple form
can I not fishtail? can you not fishtail? can he not fishtail? can we not fishtail? can you not fishtail? can they not fishtail?
V-ing form
can I not be fishtailing? can you not be fishtailing? can he not be fishtailing? can we not be fishtailing? can you not be fishtailing? can they not be fishtailing?
Perfect
can I not have fishtailed? can you not have fishtailed? can he not have fishtailed? can we not have fishtailed? can you not have fishtailed? can they not have fishtailed?
V-ing perfect
can I not have been fishtailing? can you not have been fishtailing? can he not have been fishtailing? can we not have been fishtailing? can you not have been fishtailing? can they not have been fishtailing?