could smile
Regular verb: smile - smiled- smiled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could smile
you could smile
she could smile
we could smile
you could smile
they could smile 	I could be smiling
you could be smiling
she could be smiling
we could be smiling
you could be smiling
they could be smiling	I could have smiled
you could have smiled
she could have smiled
we could have smiled
you could have smiled
they could have smiled	I could have been smiling
you could have been smiling
she could have been smiling
we could have been smiling
you could have been smiling
they could have been smiling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't smile
you couldn't smile
she couldn't smile
we couldn't smile
you couldn't smile
they couldn't smile 	I couldn't be smiling
you couldn't be smiling
she couldn't be smiling
we couldn't be smiling
you couldn't be smiling
they couldn't be smiling	I couldn't have smiled
you couldn't have smiled
she couldn't have smiled
we couldn't have smiled
you couldn't have smiled
they couldn't have smiled	I couldn't have been smiling
you couldn't have been smiling
she couldn't have been smiling
we couldn't have been smiling
you couldn't have been smiling
they couldn't have been smiling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I smile?
could you smile?
could she smile?
could we smile?
could you smile?
could they smile? 	could I be smiling?
could you be smiling?
could she be smiling?
could we be smiling?
could you be smiling?
could they be smiling? 	could I have smiled?
could you have smiled?
could she have smiled?
could we have smiled?
could you have smiled?
could they have smiled? 	could I have been smiling?
could you have been smiling?
could she have been smiling?
could we have been smiling?
could you have been smiling?
could they have been smiling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I smile?
couldn't you smile?
couldn't she smile?
couldn't we smile?
couldn't you smile?
couldn't they smile? 	couldn't I be smiling?
couldn't you be smiling?
couldn't she be smiling?
couldn't we be smiling?
couldn't you be smiling?
couldn't they be smiling? 	couldn't I have smiled?
couldn't you have smiled?
couldn't she have smiled?
couldn't we have smiled?
couldn't you have smiled?
couldn't they have smiled? 	couldn't I have been smiling?
couldn't you have been smiling?
couldn't she have been smiling?
couldn't we have been smiling?
couldn't you have been smiling?
couldn't they have been smiling?