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 couldn't soundproof
you couldn't soundproof
he couldn't soundproof
we couldn't soundproof
you couldn't soundproof
they couldn't soundproof 	I couldn't be soundproofing
you couldn't be soundproofing
he couldn't be soundproofing
we couldn't be soundproofing
you couldn't be soundproofing
they couldn't be soundproofing	I couldn't have soundproofed
you couldn't have soundproofed
he couldn't have soundproofed
we couldn't have soundproofed
you couldn't have soundproofed
they couldn't have soundproofed	I couldn't have been soundproofing
you couldn't have been soundproofing
he couldn't have been soundproofing
we couldn't have been soundproofing
you couldn't have been soundproofing
they couldn't 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 	
couldn't I soundproof?
couldn't you soundproof?
couldn't he soundproof?
couldn't we soundproof?
couldn't you soundproof?
couldn't they soundproof? 	couldn't I be soundproofing?
couldn't you be soundproofing?
couldn't he be soundproofing?
couldn't we be soundproofing?
couldn't you be soundproofing?
couldn't they be soundproofing? 	couldn't I have soundproofed?
couldn't you have soundproofed?
couldn't he have soundproofed?
couldn't we have soundproofed?
couldn't you have soundproofed?
couldn't they have soundproofed? 	couldn't I have been soundproofing?
couldn't you have been soundproofing?
couldn't he have been soundproofing?
couldn't we have been soundproofing?
couldn't you have been soundproofing?
couldn't they have been soundproofing?