could underdress
Regular verb: underdress - underdressed- underdressed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could underdress
you could underdress
he could underdress
we could underdress
you could underdress
they could underdress 	I could be underdressing
you could be underdressing
he could be underdressing
we could be underdressing
you could be underdressing
they could be underdressing	I could have underdressed
you could have underdressed
he could have underdressed
we could have underdressed
you could have underdressed
they could have underdressed	I could have been underdressing
you could have been underdressing
he could have been underdressing
we could have been underdressing
you could have been underdressing
they could have been underdressing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't underdress
you couldn't underdress
he couldn't underdress
we couldn't underdress
you couldn't underdress
they couldn't underdress 	I couldn't be underdressing
you couldn't be underdressing
he couldn't be underdressing
we couldn't be underdressing
you couldn't be underdressing
they couldn't be underdressing	I couldn't have underdressed
you couldn't have underdressed
he couldn't have underdressed
we couldn't have underdressed
you couldn't have underdressed
they couldn't have underdressed	I couldn't have been underdressing
you couldn't have been underdressing
he couldn't have been underdressing
we couldn't have been underdressing
you couldn't have been underdressing
they couldn't have been underdressing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I underdress?
could you underdress?
could he underdress?
could we underdress?
could you underdress?
could they underdress? 	could I be underdressing?
could you be underdressing?
could he be underdressing?
could we be underdressing?
could you be underdressing?
could they be underdressing? 	could I have underdressed?
could you have underdressed?
could he have underdressed?
could we have underdressed?
could you have underdressed?
could they have underdressed? 	could I have been underdressing?
could you have been underdressing?
could he have been underdressing?
could we have been underdressing?
could you have been underdressing?
could they have been underdressing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I underdress?
couldn't you underdress?
couldn't he underdress?
couldn't we underdress?
couldn't you underdress?
couldn't they underdress? 	couldn't I be underdressing?
couldn't you be underdressing?
couldn't he be underdressing?
couldn't we be underdressing?
couldn't you be underdressing?
couldn't they be underdressing? 	couldn't I have underdressed?
couldn't you have underdressed?
couldn't he have underdressed?
couldn't we have underdressed?
couldn't you have underdressed?
couldn't they have underdressed? 	couldn't I have been underdressing?
couldn't you have been underdressing?
couldn't he have been underdressing?
couldn't we have been underdressing?
couldn't you have been underdressing?
couldn't they have been underdressing?