English verb conjugation
COULD PERSIST

Regular verb: persist - persisted - persisted

Affirmation

Simple form	V-ing form
I could persist you could persist he could persist we could persist you could persist they could persist	I could be persisting you could be persisting he could be persisting we could be persisting you could be persisting they could be persisting
Perfect	V-ing perfect
I could have persisted you could have persisted he could have persisted we could have persisted you could have persisted they could have persisted	I could have been persisting you could have been persisting he could have been persisting we could have been persisting you could have been persisting they could have been persisting

Negation

Simple form	V-ing form
I couldn't persist you couldn't persist he couldn't persist we couldn't persist you couldn't persist they couldn't persist	I couldn't be persisting you couldn't be persisting he couldn't be persisting we couldn't be persisting you couldn't be persisting they couldn't be persisting
Perfect	V-ing perfect
I couldn't have persisted you couldn't have persisted he couldn't have persisted we couldn't have persisted you couldn't have persisted they couldn't have persisted	I couldn't have been persisting you couldn't have been persisting he couldn't have been persisting we couldn't have been persisting you couldn't have been persisting they couldn't have been persisting

Interrogative form

Simple form	V-ing form
could I persist? could you persist? could he persist? could we persist? could you persist? could they persist?	could I be persisting? could you be persisting? could he be persisting? could we be persisting? could you be persisting? could they be persisting?
Perfect	V-ing perfect
could I have persisted? could you have persisted? could he have persisted? could we have persisted? could you have persisted? could they have persisted?	could I have been persisting? could you have been persisting? could he have been persisting? could we have been persisting? could you have been persisting? could they have been persisting?

Interro-negative form

Simple form	V-ing form
couldn't I persist? couldn't you persist? couldn't he persist? couldn't we persist? couldn't you persist? couldn't they persist?	couldn't I be persisting? couldn't you be persisting? couldn't he be persisting? couldn't we be persisting? couldn't you be persisting? couldn't they be persisting?
Perfect	V-ing perfect
couldn't I have persisted? couldn't you have persisted? couldn't he have persisted? couldn't we have persisted? couldn't you have persisted? couldn't they have persisted?	couldn't I have been persisting? couldn't you have been persisting? couldn't he have been persisting? couldn't we have been persisting? couldn't you have been persisting? couldn't they have been persisting?