could engrain
Regular verb: engrain - engrained- engrained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could engrain
you could engrain
he could engrain
we could engrain
you could engrain
they could engrain 	I could be engraining
you could be engraining
he could be engraining
we could be engraining
you could be engraining
they could be engraining	I could have engrained
you could have engrained
he could have engrained
we could have engrained
you could have engrained
they could have engrained	I could have been engraining
you could have been engraining
he could have been engraining
we could have been engraining
you could have been engraining
they could have been engraining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't engrain
you couldn't engrain
he couldn't engrain
we couldn't engrain
you couldn't engrain
they couldn't engrain 	I couldn't be engraining
you couldn't be engraining
he couldn't be engraining
we couldn't be engraining
you couldn't be engraining
they couldn't be engraining	I couldn't have engrained
you couldn't have engrained
he couldn't have engrained
we couldn't have engrained
you couldn't have engrained
they couldn't have engrained	I couldn't have been engraining
you couldn't have been engraining
he couldn't have been engraining
we couldn't have been engraining
you couldn't have been engraining
they couldn't have been engraining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I engrain?
could you engrain?
could he engrain?
could we engrain?
could you engrain?
could they engrain? 	could I be engraining?
could you be engraining?
could he be engraining?
could we be engraining?
could you be engraining?
could they be engraining? 	could I have engrained?
could you have engrained?
could he have engrained?
could we have engrained?
could you have engrained?
could they have engrained? 	could I have been engraining?
could you have been engraining?
could he have been engraining?
could we have been engraining?
could you have been engraining?
could they have been engraining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I engrain?
couldn't you engrain?
couldn't he engrain?
couldn't we engrain?
couldn't you engrain?
couldn't they engrain? 	couldn't I be engraining?
couldn't you be engraining?
couldn't he be engraining?
couldn't we be engraining?
couldn't you be engraining?
couldn't they be engraining? 	couldn't I have engrained?
couldn't you have engrained?
couldn't he have engrained?
couldn't we have engrained?
couldn't you have engrained?
couldn't they have engrained? 	couldn't I have been engraining?
couldn't you have been engraining?
couldn't he have been engraining?
couldn't we have been engraining?
couldn't you have been engraining?
couldn't they have been engraining?