can substitute
Regular verb: substitute - substituted- substituted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can substitute
you can substitute
she can substitute
we can substitute
you can substitute
they can substitute 	I can be substituting
you can be substituting
she can be substituting
we can be substituting
you can be substituting
they can be substituting	I can have substituted
you can have substituted
she can have substituted
we can have substituted
you can have substituted
they can have substituted	I can have been substituting
you can have been substituting
she can have been substituting
we can have been substituting
you can have been substituting
they can have been substituting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't substitute
you can't substitute
she can't substitute
we can't substitute
you can't substitute
they can't substitute 	I can't be substituting
you can't be substituting
she can't be substituting
we can't be substituting
you can't be substituting
they can't be substituting	I can't have substituted
you can't have substituted
she can't have substituted
we can't have substituted
you can't have substituted
they can't have substituted	I can't have been substituting
you can't have been substituting
she can't have been substituting
we can't have been substituting
you can't have been substituting
they can't have been substituting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I substitute?
can you substitute?
can she substitute?
can we substitute?
can you substitute?
can they substitute? 	can I be substituting?
can you be substituting?
can she be substituting?
can we be substituting?
can you be substituting?
can they be substituting? 	can I have substituted?
can you have substituted?
can she have substituted?
can we have substituted?
can you have substituted?
can they have substituted? 	can I have been substituting?
can you have been substituting?
can she have been substituting?
can we have been substituting?
can you have been substituting?
can they have been substituting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I substitute?
can't you substitute?
can't she substitute?
can't we substitute?
can't you substitute?
can't they substitute? 	can't I be substituting?
can't you be substituting?
can't she be substituting?
can't we be substituting?
can't you be substituting?
can't they be substituting? 	can't I have substituted?
can't you have substituted?
can't she have substituted?
can't we have substituted?
can't you have substituted?
can't they have substituted? 	can't I have been substituting?
can't you have been substituting?
can't she have been substituting?
can't we have been substituting?
can't you have been substituting?
can't they have been substituting?