could groan
Regular verb: groan - groaned- groaned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could groan
you could groan
he could groan
we could groan
you could groan
they could groan 	I could be groaning
you could be groaning
he could be groaning
we could be groaning
you could be groaning
they could be groaning	I could have groaned
you could have groaned
he could have groaned
we could have groaned
you could have groaned
they could have groaned	I could have been groaning
you could have been groaning
he could have been groaning
we could have been groaning
you could have been groaning
they could have been groaning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't groan
you couldn't groan
he couldn't groan
we couldn't groan
you couldn't groan
they couldn't groan 	I couldn't be groaning
you couldn't be groaning
he couldn't be groaning
we couldn't be groaning
you couldn't be groaning
they couldn't be groaning	I couldn't have groaned
you couldn't have groaned
he couldn't have groaned
we couldn't have groaned
you couldn't have groaned
they couldn't have groaned	I couldn't have been groaning
you couldn't have been groaning
he couldn't have been groaning
we couldn't have been groaning
you couldn't have been groaning
they couldn't have been groaning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I groan?
could you groan?
could he groan?
could we groan?
could you groan?
could they groan? 	could I be groaning?
could you be groaning?
could he be groaning?
could we be groaning?
could you be groaning?
could they be groaning? 	could I have groaned?
could you have groaned?
could he have groaned?
could we have groaned?
could you have groaned?
could they have groaned? 	could I have been groaning?
could you have been groaning?
could he have been groaning?
could we have been groaning?
could you have been groaning?
could they have been groaning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I groan?
couldn't you groan?
couldn't he groan?
couldn't we groan?
couldn't you groan?
couldn't they groan? 	couldn't I be groaning?
couldn't you be groaning?
couldn't he be groaning?
couldn't we be groaning?
couldn't you be groaning?
couldn't they be groaning? 	couldn't I have groaned?
couldn't you have groaned?
couldn't he have groaned?
couldn't we have groaned?
couldn't you have groaned?
couldn't they have groaned? 	couldn't I have been groaning?
couldn't you have been groaning?
couldn't he have been groaning?
couldn't we have been groaning?
couldn't you have been groaning?
couldn't they have been groaning?