could sulk
Regular verb: sulk - sulked- sulked

Affirmation 	
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I could sulk
you could sulk
he could sulk
we could sulk
you could sulk
they could sulk 	I could be sulking
you could be sulking
he could be sulking
we could be sulking
you could be sulking
they could be sulking	I could have sulked
you could have sulked
he could have sulked
we could have sulked
you could have sulked
they could have sulked	I could have been sulking
you could have been sulking
he could have been sulking
we could have been sulking
you could have been sulking
they could have been sulking	

Negation 	
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I couldn't sulk
you couldn't sulk
he couldn't sulk
we couldn't sulk
you couldn't sulk
they couldn't sulk 	I couldn't be sulking
you couldn't be sulking
he couldn't be sulking
we couldn't be sulking
you couldn't be sulking
they couldn't be sulking	I couldn't have sulked
you couldn't have sulked
he couldn't have sulked
we couldn't have sulked
you couldn't have sulked
they couldn't have sulked	I couldn't have been sulking
you couldn't have been sulking
he couldn't have been sulking
we couldn't have been sulking
you couldn't have been sulking
they couldn't have been sulking	

Interrogative form 	
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could I sulk?
could you sulk?
could he sulk?
could we sulk?
could you sulk?
could they sulk? 	could I be sulking?
could you be sulking?
could he be sulking?
could we be sulking?
could you be sulking?
could they be sulking? 	could I have sulked?
could you have sulked?
could he have sulked?
could we have sulked?
could you have sulked?
could they have sulked? 	could I have been sulking?
could you have been sulking?
could he have been sulking?
could we have been sulking?
could you have been sulking?
could they have been sulking? 	

Interro-negative form 	
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couldn't I sulk?
couldn't you sulk?
couldn't he sulk?
couldn't we sulk?
couldn't you sulk?
couldn't they sulk? 	couldn't I be sulking?
couldn't you be sulking?
couldn't he be sulking?
couldn't we be sulking?
couldn't you be sulking?
couldn't they be sulking? 	couldn't I have sulked?
couldn't you have sulked?
couldn't he have sulked?
couldn't we have sulked?
couldn't you have sulked?
couldn't they have sulked? 	couldn't I have been sulking?
couldn't you have been sulking?
couldn't he have been sulking?
couldn't we have been sulking?
couldn't you have been sulking?
couldn't they have been sulking?