could discontinue
Regular verb: discontinue - discontinued- discontinued

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could discontinue
you could discontinue
he could discontinue
we could discontinue
you could discontinue
they could discontinue 	I could be discontinuing
you could be discontinuing
he could be discontinuing
we could be discontinuing
you could be discontinuing
they could be discontinuing	I could have discontinued
you could have discontinued
he could have discontinued
we could have discontinued
you could have discontinued
they could have discontinued	I could have been discontinuing
you could have been discontinuing
he could have been discontinuing
we could have been discontinuing
you could have been discontinuing
they could have been discontinuing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't discontinue
you couldn't discontinue
he couldn't discontinue
we couldn't discontinue
you couldn't discontinue
they couldn't discontinue 	I couldn't be discontinuing
you couldn't be discontinuing
he couldn't be discontinuing
we couldn't be discontinuing
you couldn't be discontinuing
they couldn't be discontinuing	I couldn't have discontinued
you couldn't have discontinued
he couldn't have discontinued
we couldn't have discontinued
you couldn't have discontinued
they couldn't have discontinued	I couldn't have been discontinuing
you couldn't have been discontinuing
he couldn't have been discontinuing
we couldn't have been discontinuing
you couldn't have been discontinuing
they couldn't have been discontinuing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I discontinue?
could you discontinue?
could he discontinue?
could we discontinue?
could you discontinue?
could they discontinue? 	could I be discontinuing?
could you be discontinuing?
could he be discontinuing?
could we be discontinuing?
could you be discontinuing?
could they be discontinuing? 	could I have discontinued?
could you have discontinued?
could he have discontinued?
could we have discontinued?
could you have discontinued?
could they have discontinued? 	could I have been discontinuing?
could you have been discontinuing?
could he have been discontinuing?
could we have been discontinuing?
could you have been discontinuing?
could they have been discontinuing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I discontinue?
couldn't you discontinue?
couldn't he discontinue?
couldn't we discontinue?
couldn't you discontinue?
couldn't they discontinue? 	couldn't I be discontinuing?
couldn't you be discontinuing?
couldn't he be discontinuing?
couldn't we be discontinuing?
couldn't you be discontinuing?
couldn't they be discontinuing? 	couldn't I have discontinued?
couldn't you have discontinued?
couldn't he have discontinued?
couldn't we have discontinued?
couldn't you have discontinued?
couldn't they have discontinued? 	couldn't I have been discontinuing?
couldn't you have been discontinuing?
couldn't he have been discontinuing?
couldn't we have been discontinuing?
couldn't you have been discontinuing?
couldn't they have been discontinuing?