English verb conjugation
COULD WATERPROOF

Regular verb: waterproof - waterproofed - waterproofed

Affirmation

Simple form	V-ing form
I could waterproof you could waterproof he could waterproof we could waterproof you could waterproof they could waterproof	I could be waterproofing you could be waterproofing he could be waterproofing we could be waterproofing you could be waterproofing they could be waterproofing
Perfect	V-ing perfect
I could have waterproofed you could have waterproofed he could have waterproofed we could have waterproofed you could have waterproofed they could have waterproofed	I could have been waterproofing you could have been waterproofing he could have been waterproofing we could have been waterproofing you could have been waterproofing they could have been waterproofing

Negation

Simple form	V-ing form
I could not waterproof you could not waterproof he could not waterproof we could not waterproof you could not waterproof they could not waterproof	I could not be waterproofing you could not be waterproofing he could not be waterproofing we could not be waterproofing you could not be waterproofing they could not be waterproofing
Perfect	V-ing perfect
I could not have waterproofed you could not have waterproofed he could not have waterproofed we could not have waterproofed you could not have waterproofed they could not have waterproofed	I could not have been waterproofing you could not have been waterproofing he could not have been waterproofing we could not have been waterproofing you could not have been waterproofing they could not have been waterproofing

Interrogative form

Simple form	V-ing form
could I waterproof? could you waterproof? could he waterproof? could we waterproof? could you waterproof? could they waterproof?	could I be waterproofing? could you be waterproofing? could he be waterproofing? could we be waterproofing? could you be waterproofing? could they be waterproofing?
Perfect	V-ing perfect
could I have waterproofed? could you have waterproofed? could he have waterproofed? could we have waterproofed? could you have waterproofed? could they have waterproofed?	could I have been waterproofing? could you have been waterproofing? could he have been waterproofing? could we have been waterproofing? could you have been waterproofing? could they have been waterproofing?

Interro-negative form

Simple form	V-ing form
could I not waterproof? could you not waterproof? could he not waterproof? could we not waterproof? could you not waterproof? could they not waterproof?	could I not be waterproofing? could you not be waterproofing? could he not be waterproofing? could we not be waterproofing? could you not be waterproofing? could they not be waterproofing?
Perfect	V-ing perfect
could I not have waterproofed? could you not have waterproofed? could he not have waterproofed? could we not have waterproofed? could you not have waterproofed? could they not have waterproofed?	could I not have been waterproofing? could you not have been waterproofing? could he not have been waterproofing? could we not have been waterproofing? could you not have been waterproofing? could they not have been waterproofing?