English verb conjugation
COULD RETARD

Regular verb: retard - retarded - retarded

Affirmation

Simple form	V-ing form
I could retard you could retard he could retard we could retard you could retard they could retard	I could be retarding you could be retarding he could be retarding we could be retarding you could be retarding they could be retarding
Perfect	V-ing perfect
I could have retarded you could have retarded he could have retarded we could have retarded you could have retarded they could have retarded	I could have been retarding you could have been retarding he could have been retarding we could have been retarding you could have been retarding they could have been retarding

Negation

Simple form	V-ing form
I couldn't retard you couldn't retard he couldn't retard we couldn't retard you couldn't retard they couldn't retard	I couldn't be retarding you couldn't be retarding he couldn't be retarding we couldn't be retarding you couldn't be retarding they couldn't be retarding
Perfect	V-ing perfect
I couldn't have retarded you couldn't have retarded he couldn't have retarded we couldn't have retarded you couldn't have retarded they couldn't have retarded	I couldn't have been retarding you couldn't have been retarding he couldn't have been retarding we couldn't have been retarding you couldn't have been retarding they couldn't have been retarding

Interrogative form

Simple form	V-ing form
could I retard? could you retard? could he retard? could we retard? could you retard? could they retard?	could I be retarding? could you be retarding? could he be retarding? could we be retarding? could you be retarding? could they be retarding?
Perfect	V-ing perfect
could I have retarded? could you have retarded? could he have retarded? could we have retarded? could you have retarded? could they have retarded?	could I have been retarding? could you have been retarding? could he have been retarding? could we have been retarding? could you have been retarding? could they have been retarding?

Interro-negative form

Simple form	V-ing form
couldn't I retard? couldn't you retard? couldn't he retard? couldn't we retard? couldn't you retard? couldn't they retard?	couldn't I be retarding? couldn't you be retarding? couldn't he be retarding? couldn't we be retarding? couldn't you be retarding? couldn't they be retarding?
Perfect	V-ing perfect
couldn't I have retarded? couldn't you have retarded? couldn't he have retarded? couldn't we have retarded? couldn't you have retarded? couldn't they have retarded?	couldn't I have been retarding? couldn't you have been retarding? couldn't he have been retarding? couldn't we have been retarding? couldn't you have been retarding? couldn't they have been retarding?