could laugh
Regular verb: laugh - laughed- laughed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could laugh
you could laugh
she could laugh
we could laugh
you could laugh
they could laugh 	I could be laughing
you could be laughing
she could be laughing
we could be laughing
you could be laughing
they could be laughing	I could have laughed
you could have laughed
she could have laughed
we could have laughed
you could have laughed
they could have laughed	I could have been laughing
you could have been laughing
she could have been laughing
we could have been laughing
you could have been laughing
they could have been laughing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't laugh
you couldn't laugh
she couldn't laugh
we couldn't laugh
you couldn't laugh
they couldn't laugh 	I couldn't be laughing
you couldn't be laughing
she couldn't be laughing
we couldn't be laughing
you couldn't be laughing
they couldn't be laughing	I couldn't have laughed
you couldn't have laughed
she couldn't have laughed
we couldn't have laughed
you couldn't have laughed
they couldn't have laughed	I couldn't have been laughing
you couldn't have been laughing
she couldn't have been laughing
we couldn't have been laughing
you couldn't have been laughing
they couldn't have been laughing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I laugh?
could you laugh?
could she laugh?
could we laugh?
could you laugh?
could they laugh? 	could I be laughing?
could you be laughing?
could she be laughing?
could we be laughing?
could you be laughing?
could they be laughing? 	could I have laughed?
could you have laughed?
could she have laughed?
could we have laughed?
could you have laughed?
could they have laughed? 	could I have been laughing?
could you have been laughing?
could she have been laughing?
could we have been laughing?
could you have been laughing?
could they have been laughing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I laugh?
couldn't you laugh?
couldn't she laugh?
couldn't we laugh?
couldn't you laugh?
couldn't they laugh? 	couldn't I be laughing?
couldn't you be laughing?
couldn't she be laughing?
couldn't we be laughing?
couldn't you be laughing?
couldn't they be laughing? 	couldn't I have laughed?
couldn't you have laughed?
couldn't she have laughed?
couldn't we have laughed?
couldn't you have laughed?
couldn't they have laughed? 	couldn't I have been laughing?
couldn't you have been laughing?
couldn't she have been laughing?
couldn't we have been laughing?
couldn't you have been laughing?
couldn't they have been laughing?