could soundproof
Regular verb: soundproof - soundproofed- soundproofed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could soundproof
you could soundproof
he could soundproof
we could soundproof
you could soundproof
they could soundproof 	I could be soundproofing
you could be soundproofing
he could be soundproofing
we could be soundproofing
you could be soundproofing
they could be soundproofing	I could have soundproofed
you could have soundproofed
he could have soundproofed
we could have soundproofed
you could have soundproofed
they could have soundproofed	I could have been soundproofing
you could have been soundproofing
he could have been soundproofing
we could have been soundproofing
you could have been soundproofing
they could have been soundproofing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not soundproof
you could not soundproof
he could not soundproof
we could not soundproof
you could not soundproof
they could not soundproof 	I could not be soundproofing
you could not be soundproofing
he could not be soundproofing
we could not be soundproofing
you could not be soundproofing
they could not be soundproofing	I could not have soundproofed
you could not have soundproofed
he could not have soundproofed
we could not have soundproofed
you could not have soundproofed
they could not have soundproofed	I could not have been soundproofing
you could not have been soundproofing
he could not have been soundproofing
we could not have been soundproofing
you could not have been soundproofing
they could not have been soundproofing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I soundproof?
could you soundproof?
could he soundproof?
could we soundproof?
could you soundproof?
could they soundproof? 	could I be soundproofing?
could you be soundproofing?
could he be soundproofing?
could we be soundproofing?
could you be soundproofing?
could they be soundproofing? 	could I have soundproofed?
could you have soundproofed?
could he have soundproofed?
could we have soundproofed?
could you have soundproofed?
could they have soundproofed? 	could I have been soundproofing?
could you have been soundproofing?
could he have been soundproofing?
could we have been soundproofing?
could you have been soundproofing?
could they have been soundproofing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not soundproof?
could you not soundproof?
could he not soundproof?
could we not soundproof?
could you not soundproof?
could they not soundproof? 	could I not be soundproofing?
could you not be soundproofing?
could he not be soundproofing?
could we not be soundproofing?
could you not be soundproofing?
could they not be soundproofing? 	could I not have soundproofed?
could you not have soundproofed?
could he not have soundproofed?
could we not have soundproofed?
could you not have soundproofed?
could they not have soundproofed? 	could I not have been soundproofing?
could you not have been soundproofing?
could he not have been soundproofing?
could we not have been soundproofing?
could you not have been soundproofing?
could they not have been soundproofing?