could carbonate
Regular verb: carbonate - carbonated- carbonated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could carbonate
you could carbonate
she could carbonate
we could carbonate
you could carbonate
they could carbonate 	I could be carbonating
you could be carbonating
she could be carbonating
we could be carbonating
you could be carbonating
they could be carbonating	I could have carbonated
you could have carbonated
she could have carbonated
we could have carbonated
you could have carbonated
they could have carbonated	I could have been carbonating
you could have been carbonating
she could have been carbonating
we could have been carbonating
you could have been carbonating
they could have been carbonating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't carbonate
you couldn't carbonate
she couldn't carbonate
we couldn't carbonate
you couldn't carbonate
they couldn't carbonate 	I couldn't be carbonating
you couldn't be carbonating
she couldn't be carbonating
we couldn't be carbonating
you couldn't be carbonating
they couldn't be carbonating	I couldn't have carbonated
you couldn't have carbonated
she couldn't have carbonated
we couldn't have carbonated
you couldn't have carbonated
they couldn't have carbonated	I couldn't have been carbonating
you couldn't have been carbonating
she couldn't have been carbonating
we couldn't have been carbonating
you couldn't have been carbonating
they couldn't have been carbonating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I carbonate?
could you carbonate?
could she carbonate?
could we carbonate?
could you carbonate?
could they carbonate? 	could I be carbonating?
could you be carbonating?
could she be carbonating?
could we be carbonating?
could you be carbonating?
could they be carbonating? 	could I have carbonated?
could you have carbonated?
could she have carbonated?
could we have carbonated?
could you have carbonated?
could they have carbonated? 	could I have been carbonating?
could you have been carbonating?
could she have been carbonating?
could we have been carbonating?
could you have been carbonating?
could they have been carbonating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I carbonate?
couldn't you carbonate?
couldn't she carbonate?
couldn't we carbonate?
couldn't you carbonate?
couldn't they carbonate? 	couldn't I be carbonating?
couldn't you be carbonating?
couldn't she be carbonating?
couldn't we be carbonating?
couldn't you be carbonating?
couldn't they be carbonating? 	couldn't I have carbonated?
couldn't you have carbonated?
couldn't she have carbonated?
couldn't we have carbonated?
couldn't you have carbonated?
couldn't they have carbonated? 	couldn't I have been carbonating?
couldn't you have been carbonating?
couldn't she have been carbonating?
couldn't we have been carbonating?
couldn't you have been carbonating?
couldn't they have been carbonating?