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 cannot trail you cannot trail he cannot trail we cannot trail you cannot trail they cannot trail	I cannot be trailing you cannot be trailing he cannot be trailing we cannot be trailing you cannot be trailing they cannot be trailing
Perfect	V-ing perfect
I cannot have trailed you cannot have trailed he cannot have trailed we cannot have trailed you cannot have trailed they cannot have trailed	I cannot have been trailing you cannot have been trailing he cannot have been trailing we cannot have been trailing you cannot have been trailing they cannot 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 I not trail? can you not trail? can he not trail? can we not trail? can you not trail? can they not trail?	can I not be trailing? can you not be trailing? can he not be trailing? can we not be trailing? can you not be trailing? can they not be trailing?
Perfect	V-ing perfect
can I not have trailed? can you not have trailed? can he not have trailed? can we not have trailed? can you not have trailed? can they not have trailed?	can I not have been trailing? can you not have been trailing? can he not have been trailing? can we not have been trailing? can you not have been trailing? can they not have been trailing?