could sob
Regular verb: sob - sobbed- sobbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could sob
you could sob
she could sob
we could sob
you could sob
they could sob 	I could be sobbing
you could be sobbing
she could be sobbing
we could be sobbing
you could be sobbing
they could be sobbing	I could have sobbed
you could have sobbed
she could have sobbed
we could have sobbed
you could have sobbed
they could have sobbed	I could have been sobbing
you could have been sobbing
she could have been sobbing
we could have been sobbing
you could have been sobbing
they could have been sobbing	

Negation 	
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I couldn't sob
you couldn't sob
she couldn't sob
we couldn't sob
you couldn't sob
they couldn't sob 	I couldn't be sobbing
you couldn't be sobbing
she couldn't be sobbing
we couldn't be sobbing
you couldn't be sobbing
they couldn't be sobbing	I couldn't have sobbed
you couldn't have sobbed
she couldn't have sobbed
we couldn't have sobbed
you couldn't have sobbed
they couldn't have sobbed	I couldn't have been sobbing
you couldn't have been sobbing
she couldn't have been sobbing
we couldn't have been sobbing
you couldn't have been sobbing
they couldn't have been sobbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I sob?
could you sob?
could she sob?
could we sob?
could you sob?
could they sob? 	could I be sobbing?
could you be sobbing?
could she be sobbing?
could we be sobbing?
could you be sobbing?
could they be sobbing? 	could I have sobbed?
could you have sobbed?
could she have sobbed?
could we have sobbed?
could you have sobbed?
could they have sobbed? 	could I have been sobbing?
could you have been sobbing?
could she have been sobbing?
could we have been sobbing?
could you have been sobbing?
could they have been sobbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I sob?
couldn't you sob?
couldn't she sob?
couldn't we sob?
couldn't you sob?
couldn't they sob? 	couldn't I be sobbing?
couldn't you be sobbing?
couldn't she be sobbing?
couldn't we be sobbing?
couldn't you be sobbing?
couldn't they be sobbing? 	couldn't I have sobbed?
couldn't you have sobbed?
couldn't she have sobbed?
couldn't we have sobbed?
couldn't you have sobbed?
couldn't they have sobbed? 	couldn't I have been sobbing?
couldn't you have been sobbing?
couldn't she have been sobbing?
couldn't we have been sobbing?
couldn't you have been sobbing?
couldn't they have been sobbing?