could tub tub
Regular verb: tub tub - tub tubed- tub tubed

, this verb may not exist. Conjugation is given as example.

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tub tub
you could tub tub
she could tub tub
we could tub tub
you could tub tub
they could tub tub 	I could be tub tubing
you could be tub tubing
she could be tub tubing
we could be tub tubing
you could be tub tubing
they could be tub tubing	I could have tub tubed
you could have tub tubed
she could have tub tubed
we could have tub tubed
you could have tub tubed
they could have tub tubed	I could have been tub tubing
you could have been tub tubing
she could have been tub tubing
we could have been tub tubing
you could have been tub tubing
they could have been tub tubing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tub tub
you couldn't tub tub
she couldn't tub tub
we couldn't tub tub
you couldn't tub tub
they couldn't tub tub 	I couldn't be tub tubing
you couldn't be tub tubing
she couldn't be tub tubing
we couldn't be tub tubing
you couldn't be tub tubing
they couldn't be tub tubing	I couldn't have tub tubed
you couldn't have tub tubed
she couldn't have tub tubed
we couldn't have tub tubed
you couldn't have tub tubed
they couldn't have tub tubed	I couldn't have been tub tubing
you couldn't have been tub tubing
she couldn't have been tub tubing
we couldn't have been tub tubing
you couldn't have been tub tubing
they couldn't have been tub tubing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tub tub?
could you tub tub?
could she tub tub?
could we tub tub?
could you tub tub?
could they tub tub? 	could I be tub tubing?
could you be tub tubing?
could she be tub tubing?
could we be tub tubing?
could you be tub tubing?
could they be tub tubing? 	could I have tub tubed?
could you have tub tubed?
could she have tub tubed?
could we have tub tubed?
could you have tub tubed?
could they have tub tubed? 	could I have been tub tubing?
could you have been tub tubing?
could she have been tub tubing?
could we have been tub tubing?
could you have been tub tubing?
could they have been tub tubing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I tub tub?
couldn't you tub tub?
couldn't she tub tub?
couldn't we tub tub?
couldn't you tub tub?
couldn't they tub tub? 	couldn't I be tub tubing?
couldn't you be tub tubing?
couldn't she be tub tubing?
couldn't we be tub tubing?
couldn't you be tub tubing?
couldn't they be tub tubing? 	couldn't I have tub tubed?
couldn't you have tub tubed?
couldn't she have tub tubed?
couldn't we have tub tubed?
couldn't you have tub tubed?
couldn't they have tub tubed? 	couldn't I have been tub tubing?
couldn't you have been tub tubing?
couldn't she have been tub tubing?
couldn't we have been tub tubing?
couldn't you have been tub tubing?
couldn't they have been tub tubing?