English verb conjugation
COULD CERTIFICATE

Regular verb: certificate - certificated - certificated

Affirmation

Simple form	V-ing form
I could certificate you could certificate she could certificate we could certificate you could certificate they could certificate	I could be certificating you could be certificating she could be certificating we could be certificating you could be certificating they could be certificating
Perfect	V-ing perfect
I could have certificated you could have certificated she could have certificated we could have certificated you could have certificated they could have certificated	I could have been certificating you could have been certificating she could have been certificating we could have been certificating you could have been certificating they could have been certificating

Negation

Simple form	V-ing form
I couldn't certificate you couldn't certificate she couldn't certificate we couldn't certificate you couldn't certificate they couldn't certificate	I couldn't be certificating you couldn't be certificating she couldn't be certificating we couldn't be certificating you couldn't be certificating they couldn't be certificating
Perfect	V-ing perfect
I couldn't have certificated you couldn't have certificated she couldn't have certificated we couldn't have certificated you couldn't have certificated they couldn't have certificated	I couldn't have been certificating you couldn't have been certificating she couldn't have been certificating we couldn't have been certificating you couldn't have been certificating they couldn't have been certificating

Interrogative form

Simple form	V-ing form
could I certificate? could you certificate? could she certificate? could we certificate? could you certificate? could they certificate?	could I be certificating? could you be certificating? could she be certificating? could we be certificating? could you be certificating? could they be certificating?
Perfect	V-ing perfect
could I have certificated? could you have certificated? could she have certificated? could we have certificated? could you have certificated? could they have certificated?	could I have been certificating? could you have been certificating? could she have been certificating? could we have been certificating? could you have been certificating? could they have been certificating?

Interro-negative form

Simple form	V-ing form
couldn't I certificate? couldn't you certificate? couldn't she certificate? couldn't we certificate? couldn't you certificate? couldn't they certificate?	couldn't I be certificating? couldn't you be certificating? couldn't she be certificating? couldn't we be certificating? couldn't you be certificating? couldn't they be certificating?
Perfect	V-ing perfect
couldn't I have certificated? couldn't you have certificated? couldn't she have certificated? couldn't we have certificated? couldn't you have certificated? couldn't they have certificated?	couldn't I have been certificating? couldn't you have been certificating? couldn't she have been certificating? couldn't we have been certificating? couldn't you have been certificating? couldn't they have been certificating?