could apologize
Regular verb: apologize - apologized- apologized

Affirmation 	
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I could apologize
you could apologize
he could apologize
we could apologize
you could apologize
they could apologize 	I could be apologizing
you could be apologizing
he could be apologizing
we could be apologizing
you could be apologizing
they could be apologizing	I could have apologized
you could have apologized
he could have apologized
we could have apologized
you could have apologized
they could have apologized	I could have been apologizing
you could have been apologizing
he could have been apologizing
we could have been apologizing
you could have been apologizing
they could have been apologizing	

Negation 	
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I couldn't apologize
you couldn't apologize
he couldn't apologize
we couldn't apologize
you couldn't apologize
they couldn't apologize 	I couldn't be apologizing
you couldn't be apologizing
he couldn't be apologizing
we couldn't be apologizing
you couldn't be apologizing
they couldn't be apologizing	I couldn't have apologized
you couldn't have apologized
he couldn't have apologized
we couldn't have apologized
you couldn't have apologized
they couldn't have apologized	I couldn't have been apologizing
you couldn't have been apologizing
he couldn't have been apologizing
we couldn't have been apologizing
you couldn't have been apologizing
they couldn't have been apologizing	

Interrogative form 	
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could I apologize?
could you apologize?
could he apologize?
could we apologize?
could you apologize?
could they apologize? 	could I be apologizing?
could you be apologizing?
could he be apologizing?
could we be apologizing?
could you be apologizing?
could they be apologizing? 	could I have apologized?
could you have apologized?
could he have apologized?
could we have apologized?
could you have apologized?
could they have apologized? 	could I have been apologizing?
could you have been apologizing?
could he have been apologizing?
could we have been apologizing?
could you have been apologizing?
could they have been apologizing? 	

Interro-negative form 	
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couldn't I apologize?
couldn't you apologize?
couldn't he apologize?
couldn't we apologize?
couldn't you apologize?
couldn't they apologize? 	couldn't I be apologizing?
couldn't you be apologizing?
couldn't he be apologizing?
couldn't we be apologizing?
couldn't you be apologizing?
couldn't they be apologizing? 	couldn't I have apologized?
couldn't you have apologized?
couldn't he have apologized?
couldn't we have apologized?
couldn't you have apologized?
couldn't they have apologized? 	couldn't I have been apologizing?
couldn't you have been apologizing?
couldn't he have been apologizing?
couldn't we have been apologizing?
couldn't you have been apologizing?
couldn't they have been apologizing?