could maintain
Regular verb: maintain - maintained- maintained

Affirmation 	
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I could maintain
you could maintain
he could maintain
we could maintain
you could maintain
they could maintain 	I could be maintaining
you could be maintaining
he could be maintaining
we could be maintaining
you could be maintaining
they could be maintaining	I could have maintained
you could have maintained
he could have maintained
we could have maintained
you could have maintained
they could have maintained	I could have been maintaining
you could have been maintaining
he could have been maintaining
we could have been maintaining
you could have been maintaining
they could have been maintaining	

Negation 	
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I couldn't maintain
you couldn't maintain
he couldn't maintain
we couldn't maintain
you couldn't maintain
they couldn't maintain 	I couldn't be maintaining
you couldn't be maintaining
he couldn't be maintaining
we couldn't be maintaining
you couldn't be maintaining
they couldn't be maintaining	I couldn't have maintained
you couldn't have maintained
he couldn't have maintained
we couldn't have maintained
you couldn't have maintained
they couldn't have maintained	I couldn't have been maintaining
you couldn't have been maintaining
he couldn't have been maintaining
we couldn't have been maintaining
you couldn't have been maintaining
they couldn't have been maintaining	

Interrogative form 	
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could I maintain?
could you maintain?
could he maintain?
could we maintain?
could you maintain?
could they maintain? 	could I be maintaining?
could you be maintaining?
could he be maintaining?
could we be maintaining?
could you be maintaining?
could they be maintaining? 	could I have maintained?
could you have maintained?
could he have maintained?
could we have maintained?
could you have maintained?
could they have maintained? 	could I have been maintaining?
could you have been maintaining?
could he have been maintaining?
could we have been maintaining?
could you have been maintaining?
could they have been maintaining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I maintain?
couldn't you maintain?
couldn't he maintain?
couldn't we maintain?
couldn't you maintain?
couldn't they maintain? 	couldn't I be maintaining?
couldn't you be maintaining?
couldn't he be maintaining?
couldn't we be maintaining?
couldn't you be maintaining?
couldn't they be maintaining? 	couldn't I have maintained?
couldn't you have maintained?
couldn't he have maintained?
couldn't we have maintained?
couldn't you have maintained?
couldn't they have maintained? 	couldn't I have been maintaining?
couldn't you have been maintaining?
couldn't he have been maintaining?
couldn't we have been maintaining?
couldn't you have been maintaining?
couldn't they have been maintaining?