could shark
Regular verb: shark - sharked- sharked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shark
you could shark
she could shark
we could shark
you could shark
they could shark 	I could be sharking
you could be sharking
she could be sharking
we could be sharking
you could be sharking
they could be sharking	I could have sharked
you could have sharked
she could have sharked
we could have sharked
you could have sharked
they could have sharked	I could have been sharking
you could have been sharking
she could have been sharking
we could have been sharking
you could have been sharking
they could have been sharking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't shark
you couldn't shark
she couldn't shark
we couldn't shark
you couldn't shark
they couldn't shark 	I couldn't be sharking
you couldn't be sharking
she couldn't be sharking
we couldn't be sharking
you couldn't be sharking
they couldn't be sharking	I couldn't have sharked
you couldn't have sharked
she couldn't have sharked
we couldn't have sharked
you couldn't have sharked
they couldn't have sharked	I couldn't have been sharking
you couldn't have been sharking
she couldn't have been sharking
we couldn't have been sharking
you couldn't have been sharking
they couldn't have been sharking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shark?
could you shark?
could she shark?
could we shark?
could you shark?
could they shark? 	could I be sharking?
could you be sharking?
could she be sharking?
could we be sharking?
could you be sharking?
could they be sharking? 	could I have sharked?
could you have sharked?
could she have sharked?
could we have sharked?
could you have sharked?
could they have sharked? 	could I have been sharking?
could you have been sharking?
could she have been sharking?
could we have been sharking?
could you have been sharking?
could they have been sharking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I shark?
couldn't you shark?
couldn't she shark?
couldn't we shark?
couldn't you shark?
couldn't they shark? 	couldn't I be sharking?
couldn't you be sharking?
couldn't she be sharking?
couldn't we be sharking?
couldn't you be sharking?
couldn't they be sharking? 	couldn't I have sharked?
couldn't you have sharked?
couldn't she have sharked?
couldn't we have sharked?
couldn't you have sharked?
couldn't they have sharked? 	couldn't I have been sharking?
couldn't you have been sharking?
couldn't she have been sharking?
couldn't we have been sharking?
couldn't you have been sharking?
couldn't they have been sharking?