English verb conjugation
COULD PERSIST

Regular verb: persist - persisted - persisted

Affirmation

Simple form	V-ing form
I could persist you could persist she could persist we could persist you could persist they could persist	I could be persisting you could be persisting she 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 she 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 she 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 she 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 she 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 she 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 she 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 she persist? could we persist? could you persist? could they persist?	could I be persisting? could you be persisting? could she 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 she 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 she 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 she 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 she 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 she 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 she have been persisting? couldn't we have been persisting? couldn't you have been persisting? couldn't they have been persisting?