could patent
Regular verb: patent - patented- patented

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could patent
you could patent
she could patent
we could patent
you could patent
they could patent 	I could be patenting
you could be patenting
she could be patenting
we could be patenting
you could be patenting
they could be patenting	I could have patented
you could have patented
she could have patented
we could have patented
you could have patented
they could have patented	I could have been patenting
you could have been patenting
she could have been patenting
we could have been patenting
you could have been patenting
they could have been patenting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't patent
you couldn't patent
she couldn't patent
we couldn't patent
you couldn't patent
they couldn't patent 	I couldn't be patenting
you couldn't be patenting
she couldn't be patenting
we couldn't be patenting
you couldn't be patenting
they couldn't be patenting	I couldn't have patented
you couldn't have patented
she couldn't have patented
we couldn't have patented
you couldn't have patented
they couldn't have patented	I couldn't have been patenting
you couldn't have been patenting
she couldn't have been patenting
we couldn't have been patenting
you couldn't have been patenting
they couldn't have been patenting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I patent?
could you patent?
could she patent?
could we patent?
could you patent?
could they patent? 	could I be patenting?
could you be patenting?
could she be patenting?
could we be patenting?
could you be patenting?
could they be patenting? 	could I have patented?
could you have patented?
could she have patented?
could we have patented?
could you have patented?
could they have patented? 	could I have been patenting?
could you have been patenting?
could she have been patenting?
could we have been patenting?
could you have been patenting?
could they have been patenting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I patent?
couldn't you patent?
couldn't she patent?
couldn't we patent?
couldn't you patent?
couldn't they patent? 	couldn't I be patenting?
couldn't you be patenting?
couldn't she be patenting?
couldn't we be patenting?
couldn't you be patenting?
couldn't they be patenting? 	couldn't I have patented?
couldn't you have patented?
couldn't she have patented?
couldn't we have patented?
couldn't you have patented?
couldn't they have patented? 	couldn't I have been patenting?
couldn't you have been patenting?
couldn't she have been patenting?
couldn't we have been patenting?
couldn't you have been patenting?
couldn't they have been patenting?