could boo
Regular verb: boo - booed- booed

Affirmation 	
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I could boo
you could boo
he could boo
we could boo
you could boo
they could boo 	I could be booing
you could be booing
he could be booing
we could be booing
you could be booing
they could be booing	I could have booed
you could have booed
he could have booed
we could have booed
you could have booed
they could have booed	I could have been booing
you could have been booing
he could have been booing
we could have been booing
you could have been booing
they could have been booing	

Negation 	
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I couldn't boo
you couldn't boo
he couldn't boo
we couldn't boo
you couldn't boo
they couldn't boo 	I couldn't be booing
you couldn't be booing
he couldn't be booing
we couldn't be booing
you couldn't be booing
they couldn't be booing	I couldn't have booed
you couldn't have booed
he couldn't have booed
we couldn't have booed
you couldn't have booed
they couldn't have booed	I couldn't have been booing
you couldn't have been booing
he couldn't have been booing
we couldn't have been booing
you couldn't have been booing
they couldn't have been booing	

Interrogative form 	
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could I boo?
could you boo?
could he boo?
could we boo?
could you boo?
could they boo? 	could I be booing?
could you be booing?
could he be booing?
could we be booing?
could you be booing?
could they be booing? 	could I have booed?
could you have booed?
could he have booed?
could we have booed?
could you have booed?
could they have booed? 	could I have been booing?
could you have been booing?
could he have been booing?
could we have been booing?
could you have been booing?
could they have been booing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I boo?
couldn't you boo?
couldn't he boo?
couldn't we boo?
couldn't you boo?
couldn't they boo? 	couldn't I be booing?
couldn't you be booing?
couldn't he be booing?
couldn't we be booing?
couldn't you be booing?
couldn't they be booing? 	couldn't I have booed?
couldn't you have booed?
couldn't he have booed?
couldn't we have booed?
couldn't you have booed?
couldn't they have booed? 	couldn't I have been booing?
couldn't you have been booing?
couldn't he have been booing?
couldn't we have been booing?
couldn't you have been booing?
couldn't they have been booing?