could impute
Regular verb: impute - imputed- imputed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could impute
you could impute
she could impute
we could impute
you could impute
they could impute 	I could be imputing
you could be imputing
she could be imputing
we could be imputing
you could be imputing
they could be imputing	I could have imputed
you could have imputed
she could have imputed
we could have imputed
you could have imputed
they could have imputed	I could have been imputing
you could have been imputing
she could have been imputing
we could have been imputing
you could have been imputing
they could have been imputing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't impute
you couldn't impute
she couldn't impute
we couldn't impute
you couldn't impute
they couldn't impute 	I couldn't be imputing
you couldn't be imputing
she couldn't be imputing
we couldn't be imputing
you couldn't be imputing
they couldn't be imputing	I couldn't have imputed
you couldn't have imputed
she couldn't have imputed
we couldn't have imputed
you couldn't have imputed
they couldn't have imputed	I couldn't have been imputing
you couldn't have been imputing
she couldn't have been imputing
we couldn't have been imputing
you couldn't have been imputing
they couldn't have been imputing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I impute?
could you impute?
could she impute?
could we impute?
could you impute?
could they impute? 	could I be imputing?
could you be imputing?
could she be imputing?
could we be imputing?
could you be imputing?
could they be imputing? 	could I have imputed?
could you have imputed?
could she have imputed?
could we have imputed?
could you have imputed?
could they have imputed? 	could I have been imputing?
could you have been imputing?
could she have been imputing?
could we have been imputing?
could you have been imputing?
could they have been imputing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I impute?
couldn't you impute?
couldn't she impute?
couldn't we impute?
couldn't you impute?
couldn't they impute? 	couldn't I be imputing?
couldn't you be imputing?
couldn't she be imputing?
couldn't we be imputing?
couldn't you be imputing?
couldn't they be imputing? 	couldn't I have imputed?
couldn't you have imputed?
couldn't she have imputed?
couldn't we have imputed?
couldn't you have imputed?
couldn't they have imputed? 	couldn't I have been imputing?
couldn't you have been imputing?
couldn't she have been imputing?
couldn't we have been imputing?
couldn't you have been imputing?
couldn't they have been imputing?