could shallow
Regular verb: shallow - shallowed- shallowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shallow
you could shallow
he could shallow
we could shallow
you could shallow
they could shallow 	I could be shallowing
you could be shallowing
he could be shallowing
we could be shallowing
you could be shallowing
they could be shallowing	I could have shallowed
you could have shallowed
he could have shallowed
we could have shallowed
you could have shallowed
they could have shallowed	I could have been shallowing
you could have been shallowing
he could have been shallowing
we could have been shallowing
you could have been shallowing
they could have been shallowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't shallow
you couldn't shallow
he couldn't shallow
we couldn't shallow
you couldn't shallow
they couldn't shallow 	I couldn't be shallowing
you couldn't be shallowing
he couldn't be shallowing
we couldn't be shallowing
you couldn't be shallowing
they couldn't be shallowing	I couldn't have shallowed
you couldn't have shallowed
he couldn't have shallowed
we couldn't have shallowed
you couldn't have shallowed
they couldn't have shallowed	I couldn't have been shallowing
you couldn't have been shallowing
he couldn't have been shallowing
we couldn't have been shallowing
you couldn't have been shallowing
they couldn't have been shallowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shallow?
could you shallow?
could he shallow?
could we shallow?
could you shallow?
could they shallow? 	could I be shallowing?
could you be shallowing?
could he be shallowing?
could we be shallowing?
could you be shallowing?
could they be shallowing? 	could I have shallowed?
could you have shallowed?
could he have shallowed?
could we have shallowed?
could you have shallowed?
could they have shallowed? 	could I have been shallowing?
could you have been shallowing?
could he have been shallowing?
could we have been shallowing?
could you have been shallowing?
could they have been shallowing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I shallow?
couldn't you shallow?
couldn't he shallow?
couldn't we shallow?
couldn't you shallow?
couldn't they shallow? 	couldn't I be shallowing?
couldn't you be shallowing?
couldn't he be shallowing?
couldn't we be shallowing?
couldn't you be shallowing?
couldn't they be shallowing? 	couldn't I have shallowed?
couldn't you have shallowed?
couldn't he have shallowed?
couldn't we have shallowed?
couldn't you have shallowed?
couldn't they have shallowed? 	couldn't I have been shallowing?
couldn't you have been shallowing?
couldn't he have been shallowing?
couldn't we have been shallowing?
couldn't you have been shallowing?
couldn't they have been shallowing?