English verb conjugation
COULD SUBSTANTIATE

Regular verb: substantiate - substantiated - substantiated

Affirmation

Simple form	V-ing form
I could substantiate you could substantiate she could substantiate we could substantiate you could substantiate they could substantiate	I could be substantiating you could be substantiating she could be substantiating we could be substantiating you could be substantiating they could be substantiating
Perfect	V-ing perfect
I could have substantiated you could have substantiated she could have substantiated we could have substantiated you could have substantiated they could have substantiated	I could have been substantiating you could have been substantiating she could have been substantiating we could have been substantiating you could have been substantiating they could have been substantiating

Negation

Simple form	V-ing form
I couldn't substantiate you couldn't substantiate she couldn't substantiate we couldn't substantiate you couldn't substantiate they couldn't substantiate	I couldn't be substantiating you couldn't be substantiating she couldn't be substantiating we couldn't be substantiating you couldn't be substantiating they couldn't be substantiating
Perfect	V-ing perfect
I couldn't have substantiated you couldn't have substantiated she couldn't have substantiated we couldn't have substantiated you couldn't have substantiated they couldn't have substantiated	I couldn't have been substantiating you couldn't have been substantiating she couldn't have been substantiating we couldn't have been substantiating you couldn't have been substantiating they couldn't have been substantiating

Interrogative form

Simple form	V-ing form
could I substantiate? could you substantiate? could she substantiate? could we substantiate? could you substantiate? could they substantiate?	could I be substantiating? could you be substantiating? could she be substantiating? could we be substantiating? could you be substantiating? could they be substantiating?
Perfect	V-ing perfect
could I have substantiated? could you have substantiated? could she have substantiated? could we have substantiated? could you have substantiated? could they have substantiated?	could I have been substantiating? could you have been substantiating? could she have been substantiating? could we have been substantiating? could you have been substantiating? could they have been substantiating?

Interro-negative form

Simple form	V-ing form
couldn't I substantiate? couldn't you substantiate? couldn't she substantiate? couldn't we substantiate? couldn't you substantiate? couldn't they substantiate?	couldn't I be substantiating? couldn't you be substantiating? couldn't she be substantiating? couldn't we be substantiating? couldn't you be substantiating? couldn't they be substantiating?
Perfect	V-ing perfect
couldn't I have substantiated? couldn't you have substantiated? couldn't she have substantiated? couldn't we have substantiated? couldn't you have substantiated? couldn't they have substantiated?	couldn't I have been substantiating? couldn't you have been substantiating? couldn't she have been substantiating? couldn't we have been substantiating? couldn't you have been substantiating? couldn't they have been substantiating?