could certificate
Regular verb: certificate - certificated- certificated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could certificate
you could certificate
he could certificate
we could certificate
you could certificate
they could certificate 	I could be certificating
you could be certificating
he could be certificating
we could be certificating
you could be certificating
they could be certificating	I could have certificated
you could have certificated
he 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
he 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 	Perfect 	V-ing perfect 	
I could not certificate
you could not certificate
he could not certificate
we could not certificate
you could not certificate
they could not certificate 	I could not be certificating
you could not be certificating
he could not be certificating
we could not be certificating
you could not be certificating
they could not be certificating	I could not have certificated
you could not have certificated
he could not have certificated
we could not have certificated
you could not have certificated
they could not have certificated	I could not have been certificating
you could not have been certificating
he could not have been certificating
we could not have been certificating
you could not have been certificating
they could not have been certificating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I certificate?
could you certificate?
could he certificate?
could we certificate?
could you certificate?
could they certificate? 	could I be certificating?
could you be certificating?
could he be certificating?
could we be certificating?
could you be certificating?
could they be certificating? 	could I have certificated?
could you have certificated?
could he 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 he 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 	Perfect 	V-ing perfect 	
could I not certificate?
could you not certificate?
could he not certificate?
could we not certificate?
could you not certificate?
could they not certificate? 	could I not be certificating?
could you not be certificating?
could he not be certificating?
could we not be certificating?
could you not be certificating?
could they not be certificating? 	could I not have certificated?
could you not have certificated?
could he not have certificated?
could we not have certificated?
could you not have certificated?
could they not have certificated? 	could I not have been certificating?
could you not have been certificating?
could he not have been certificating?
could we not have been certificating?
could you not have been certificating?
could they not have been certificating?