English verb conjugation
COULD OVERGRADE

Regular verb: overgrade - overgraded - overgraded

Affirmation

Simple form	V-ing form
I could overgrade you could overgrade she could overgrade we could overgrade you could overgrade they could overgrade	I could be overgrading you could be overgrading she could be overgrading we could be overgrading you could be overgrading they could be overgrading
Perfect	V-ing perfect
I could have overgraded you could have overgraded she could have overgraded we could have overgraded you could have overgraded they could have overgraded	I could have been overgrading you could have been overgrading she could have been overgrading we could have been overgrading you could have been overgrading they could have been overgrading

Negation

Simple form	V-ing form
I couldn't overgrade you couldn't overgrade she couldn't overgrade we couldn't overgrade you couldn't overgrade they couldn't overgrade	I couldn't be overgrading you couldn't be overgrading she couldn't be overgrading we couldn't be overgrading you couldn't be overgrading they couldn't be overgrading
Perfect	V-ing perfect
I couldn't have overgraded you couldn't have overgraded she couldn't have overgraded we couldn't have overgraded you couldn't have overgraded they couldn't have overgraded	I couldn't have been overgrading you couldn't have been overgrading she couldn't have been overgrading we couldn't have been overgrading you couldn't have been overgrading they couldn't have been overgrading

Interrogative form

Simple form	V-ing form
could I overgrade? could you overgrade? could she overgrade? could we overgrade? could you overgrade? could they overgrade?	could I be overgrading? could you be overgrading? could she be overgrading? could we be overgrading? could you be overgrading? could they be overgrading?
Perfect	V-ing perfect
could I have overgraded? could you have overgraded? could she have overgraded? could we have overgraded? could you have overgraded? could they have overgraded?	could I have been overgrading? could you have been overgrading? could she have been overgrading? could we have been overgrading? could you have been overgrading? could they have been overgrading?

Interro-negative form

Simple form	V-ing form
couldn't I overgrade? couldn't you overgrade? couldn't she overgrade? couldn't we overgrade? couldn't you overgrade? couldn't they overgrade?	couldn't I be overgrading? couldn't you be overgrading? couldn't she be overgrading? couldn't we be overgrading? couldn't you be overgrading? couldn't they be overgrading?
Perfect	V-ing perfect
couldn't I have overgraded? couldn't you have overgraded? couldn't she have overgraded? couldn't we have overgraded? couldn't you have overgraded? couldn't they have overgraded?	couldn't I have been overgrading? couldn't you have been overgrading? couldn't she have been overgrading? couldn't we have been overgrading? couldn't you have been overgrading? couldn't they have been overgrading?