could invest
Regular verb: invest - invested- invested

Affirmation 	
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I could invest
you could invest
she could invest
we could invest
you could invest
they could invest 	I could be investing
you could be investing
she could be investing
we could be investing
you could be investing
they could be investing	I could have invested
you could have invested
she could have invested
we could have invested
you could have invested
they could have invested	I could have been investing
you could have been investing
she could have been investing
we could have been investing
you could have been investing
they could have been investing	

Negation 	
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I couldn't invest
you couldn't invest
she couldn't invest
we couldn't invest
you couldn't invest
they couldn't invest 	I couldn't be investing
you couldn't be investing
she couldn't be investing
we couldn't be investing
you couldn't be investing
they couldn't be investing	I couldn't have invested
you couldn't have invested
she couldn't have invested
we couldn't have invested
you couldn't have invested
they couldn't have invested	I couldn't have been investing
you couldn't have been investing
she couldn't have been investing
we couldn't have been investing
you couldn't have been investing
they couldn't have been investing	

Interrogative form 	
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could I invest?
could you invest?
could she invest?
could we invest?
could you invest?
could they invest? 	could I be investing?
could you be investing?
could she be investing?
could we be investing?
could you be investing?
could they be investing? 	could I have invested?
could you have invested?
could she have invested?
could we have invested?
could you have invested?
could they have invested? 	could I have been investing?
could you have been investing?
could she have been investing?
could we have been investing?
could you have been investing?
could they have been investing? 	

Interro-negative form 	
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couldn't I invest?
couldn't you invest?
couldn't she invest?
couldn't we invest?
couldn't you invest?
couldn't they invest? 	couldn't I be investing?
couldn't you be investing?
couldn't she be investing?
couldn't we be investing?
couldn't you be investing?
couldn't they be investing? 	couldn't I have invested?
couldn't you have invested?
couldn't she have invested?
couldn't we have invested?
couldn't you have invested?
couldn't they have invested? 	couldn't I have been investing?
couldn't you have been investing?
couldn't she have been investing?
couldn't we have been investing?
couldn't you have been investing?
couldn't they have been investing?