English verb conjugation
COULD PREEXIST

Regular verb: preexist - preexisted - preexisted

Affirmation

Simple form	V-ing form
I could preexist you could preexist he could preexist we could preexist you could preexist they could preexist	I could be preexisting you could be preexisting he could be preexisting we could be preexisting you could be preexisting they could be preexisting
Perfect	V-ing perfect
I could have preexisted you could have preexisted he could have preexisted we could have preexisted you could have preexisted they could have preexisted	I could have been preexisting you could have been preexisting he could have been preexisting we could have been preexisting you could have been preexisting they could have been preexisting

Negation

Simple form	V-ing form
I couldn't preexist you couldn't preexist he couldn't preexist we couldn't preexist you couldn't preexist they couldn't preexist	I couldn't be preexisting you couldn't be preexisting he couldn't be preexisting we couldn't be preexisting you couldn't be preexisting they couldn't be preexisting
Perfect	V-ing perfect
I couldn't have preexisted you couldn't have preexisted he couldn't have preexisted we couldn't have preexisted you couldn't have preexisted they couldn't have preexisted	I couldn't have been preexisting you couldn't have been preexisting he couldn't have been preexisting we couldn't have been preexisting you couldn't have been preexisting they couldn't have been preexisting

Interrogative form

Simple form	V-ing form
could I preexist? could you preexist? could he preexist? could we preexist? could you preexist? could they preexist?	could I be preexisting? could you be preexisting? could he be preexisting? could we be preexisting? could you be preexisting? could they be preexisting?
Perfect	V-ing perfect
could I have preexisted? could you have preexisted? could he have preexisted? could we have preexisted? could you have preexisted? could they have preexisted?	could I have been preexisting? could you have been preexisting? could he have been preexisting? could we have been preexisting? could you have been preexisting? could they have been preexisting?

Interro-negative form

Simple form	V-ing form
couldn't I preexist? couldn't you preexist? couldn't he preexist? couldn't we preexist? couldn't you preexist? couldn't they preexist?	couldn't I be preexisting? couldn't you be preexisting? couldn't he be preexisting? couldn't we be preexisting? couldn't you be preexisting? couldn't they be preexisting?
Perfect	V-ing perfect
couldn't I have preexisted? couldn't you have preexisted? couldn't he have preexisted? couldn't we have preexisted? couldn't you have preexisted? couldn't they have preexisted?	couldn't I have been preexisting? couldn't you have been preexisting? couldn't he have been preexisting? couldn't we have been preexisting? couldn't you have been preexisting? couldn't they have been preexisting?