English verb conjugation
COULD DECUPLE

Regular verb: decuple - decupled - decupled

Affirmation

Simple form	V-ing form
I could decuple you could decuple she could decuple we could decuple you could decuple they could decuple	I could be decupling you could be decupling she could be decupling we could be decupling you could be decupling they could be decupling
Perfect	V-ing perfect
I could have decupled you could have decupled she could have decupled we could have decupled you could have decupled they could have decupled	I could have been decupling you could have been decupling she could have been decupling we could have been decupling you could have been decupling they could have been decupling

Negation

Simple form	V-ing form
I couldn't decuple you couldn't decuple she couldn't decuple we couldn't decuple you couldn't decuple they couldn't decuple	I couldn't be decupling you couldn't be decupling she couldn't be decupling we couldn't be decupling you couldn't be decupling they couldn't be decupling
Perfect	V-ing perfect
I couldn't have decupled you couldn't have decupled she couldn't have decupled we couldn't have decupled you couldn't have decupled they couldn't have decupled	I couldn't have been decupling you couldn't have been decupling she couldn't have been decupling we couldn't have been decupling you couldn't have been decupling they couldn't have been decupling

Interrogative form

Simple form	V-ing form
could I decuple? could you decuple? could she decuple? could we decuple? could you decuple? could they decuple?	could I be decupling? could you be decupling? could she be decupling? could we be decupling? could you be decupling? could they be decupling?
Perfect	V-ing perfect
could I have decupled? could you have decupled? could she have decupled? could we have decupled? could you have decupled? could they have decupled?	could I have been decupling? could you have been decupling? could she have been decupling? could we have been decupling? could you have been decupling? could they have been decupling?

Interro-negative form

Simple form	V-ing form
couldn't I decuple? couldn't you decuple? couldn't she decuple? couldn't we decuple? couldn't you decuple? couldn't they decuple?	couldn't I be decupling? couldn't you be decupling? couldn't she be decupling? couldn't we be decupling? couldn't you be decupling? couldn't they be decupling?
Perfect	V-ing perfect
couldn't I have decupled? couldn't you have decupled? couldn't she have decupled? couldn't we have decupled? couldn't you have decupled? couldn't they have decupled?	couldn't I have been decupling? couldn't you have been decupling? couldn't she have been decupling? couldn't we have been decupling? couldn't you have been decupling? couldn't they have been decupling?