could intercalate
Regular verb: intercalate - intercalated- intercalated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could intercalate
you could intercalate
he could intercalate
we could intercalate
you could intercalate
they could intercalate 	I could be intercalating
you could be intercalating
he could be intercalating
we could be intercalating
you could be intercalating
they could be intercalating	I could have intercalated
you could have intercalated
he could have intercalated
we could have intercalated
you could have intercalated
they could have intercalated	I could have been intercalating
you could have been intercalating
he could have been intercalating
we could have been intercalating
you could have been intercalating
they could have been intercalating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't intercalate
you couldn't intercalate
he couldn't intercalate
we couldn't intercalate
you couldn't intercalate
they couldn't intercalate 	I couldn't be intercalating
you couldn't be intercalating
he couldn't be intercalating
we couldn't be intercalating
you couldn't be intercalating
they couldn't be intercalating	I couldn't have intercalated
you couldn't have intercalated
he couldn't have intercalated
we couldn't have intercalated
you couldn't have intercalated
they couldn't have intercalated	I couldn't have been intercalating
you couldn't have been intercalating
he couldn't have been intercalating
we couldn't have been intercalating
you couldn't have been intercalating
they couldn't have been intercalating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I intercalate?
could you intercalate?
could he intercalate?
could we intercalate?
could you intercalate?
could they intercalate? 	could I be intercalating?
could you be intercalating?
could he be intercalating?
could we be intercalating?
could you be intercalating?
could they be intercalating? 	could I have intercalated?
could you have intercalated?
could he have intercalated?
could we have intercalated?
could you have intercalated?
could they have intercalated? 	could I have been intercalating?
could you have been intercalating?
could he have been intercalating?
could we have been intercalating?
could you have been intercalating?
could they have been intercalating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I intercalate?
couldn't you intercalate?
couldn't he intercalate?
couldn't we intercalate?
couldn't you intercalate?
couldn't they intercalate? 	couldn't I be intercalating?
couldn't you be intercalating?
couldn't he be intercalating?
couldn't we be intercalating?
couldn't you be intercalating?
couldn't they be intercalating? 	couldn't I have intercalated?
couldn't you have intercalated?
couldn't he have intercalated?
couldn't we have intercalated?
couldn't you have intercalated?
couldn't they have intercalated? 	couldn't I have been intercalating?
couldn't you have been intercalating?
couldn't he have been intercalating?
couldn't we have been intercalating?
couldn't you have been intercalating?
couldn't they have been intercalating?