English verb conjugation
CAN TRAIL

Regular verb: trail - trailed - trailed

Affirmation

Simple form	V-ing form
I can trail you can trail he can trail we can trail you can trail they can trail	I can be trailing you can be trailing he can be trailing we can be trailing you can be trailing they can be trailing
Perfect	V-ing perfect
I can have trailed you can have trailed he can have trailed we can have trailed you can have trailed they can have trailed	I can have been trailing you can have been trailing he can have been trailing we can have been trailing you can have been trailing they can have been trailing

Negation

Simple form	V-ing form
I can't trail you can't trail he can't trail we can't trail you can't trail they can't trail	I can't be trailing you can't be trailing he can't be trailing we can't be trailing you can't be trailing they can't be trailing
Perfect	V-ing perfect
I can't have trailed you can't have trailed he can't have trailed we can't have trailed you can't have trailed they can't have trailed	I can't have been trailing you can't have been trailing he can't have been trailing we can't have been trailing you can't have been trailing they can't have been trailing

Interrogative form

Simple form	V-ing form
can I trail? can you trail? can he trail? can we trail? can you trail? can they trail?	can I be trailing? can you be trailing? can he be trailing? can we be trailing? can you be trailing? can they be trailing?
Perfect	V-ing perfect
can I have trailed? can you have trailed? can he have trailed? can we have trailed? can you have trailed? can they have trailed?	can I have been trailing? can you have been trailing? can he have been trailing? can we have been trailing? can you have been trailing? can they have been trailing?

Interro-negative form

Simple form	V-ing form
can't I trail? can't you trail? can't he trail? can't we trail? can't you trail? can't they trail?	can't I be trailing? can't you be trailing? can't he be trailing? can't we be trailing? can't you be trailing? can't they be trailing?
Perfect	V-ing perfect
can't I have trailed? can't you have trailed? can't he have trailed? can't we have trailed? can't you have trailed? can't they have trailed?	can't I have been trailing? can't you have been trailing? can't he have been trailing? can't we have been trailing? can't you have been trailing? can't they have been trailing?