can trek
Regular verb: trek - trekked- trekked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can trek
you can trek
she can trek
we can trek
you can trek
they can trek 	I can be trekking
you can be trekking
she can be trekking
we can be trekking
you can be trekking
they can be trekking	I can have trekked
you can have trekked
she can have trekked
we can have trekked
you can have trekked
they can have trekked	I can have been trekking
you can have been trekking
she can have been trekking
we can have been trekking
you can have been trekking
they can have been trekking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't trek
you can't trek
she can't trek
we can't trek
you can't trek
they can't trek 	I can't be trekking
you can't be trekking
she can't be trekking
we can't be trekking
you can't be trekking
they can't be trekking	I can't have trekked
you can't have trekked
she can't have trekked
we can't have trekked
you can't have trekked
they can't have trekked	I can't have been trekking
you can't have been trekking
she can't have been trekking
we can't have been trekking
you can't have been trekking
they can't have been trekking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I trek?
can you trek?
can she trek?
can we trek?
can you trek?
can they trek? 	can I be trekking?
can you be trekking?
can she be trekking?
can we be trekking?
can you be trekking?
can they be trekking? 	can I have trekked?
can you have trekked?
can she have trekked?
can we have trekked?
can you have trekked?
can they have trekked? 	can I have been trekking?
can you have been trekking?
can she have been trekking?
can we have been trekking?
can you have been trekking?
can they have been trekking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I trek?
can't you trek?
can't she trek?
can't we trek?
can't you trek?
can't they trek? 	can't I be trekking?
can't you be trekking?
can't she be trekking?
can't we be trekking?
can't you be trekking?
can't they be trekking? 	can't I have trekked?
can't you have trekked?
can't she have trekked?
can't we have trekked?
can't you have trekked?
can't they have trekked? 	can't I have been trekking?
can't you have been trekking?
can't she have been trekking?
can't we have been trekking?
can't you have been trekking?
can't they have been trekking?