can sob
Regular verb: sob - sobbed- sobbed

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't sob
you can't sob
he can't sob
we can't sob
you can't sob
they can't sob 	I can't be sobbing
you can't be sobbing
he can't be sobbing
we can't be sobbing
you can't be sobbing
they can't be sobbing	I can't have sobbed
you can't have sobbed
he can't have sobbed
we can't have sobbed
you can't have sobbed
they can't have sobbed	I can't have been sobbing
you can't have been sobbing
he can't have been sobbing
we can't have been sobbing
you can't have been sobbing
they can't have been sobbing	

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

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