could change
Verbe régulier : change - changed- changed

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I could change
you could change
she could change
we could change
you could change
they could change 	I could be changing
you could be changing
she could be changing
we could be changing
you could be changing
they could be changing	I could have changed
you could have changed
she could have changed
we could have changed
you could have changed
they could have changed	I could have been changing
you could have been changing
she could have been changing
we could have been changing
you could have been changing
they could have been changing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I couldn't change
you couldn't change
she couldn't change
we couldn't change
you couldn't change
they couldn't change 	I couldn't be changing
you couldn't be changing
she couldn't be changing
we couldn't be changing
you couldn't be changing
they couldn't be changing	I couldn't have changed
you couldn't have changed
she couldn't have changed
we couldn't have changed
you couldn't have changed
they couldn't have changed	I couldn't have been changing
you couldn't have been changing
she couldn't have been changing
we couldn't have been changing
you couldn't have been changing
they couldn't have been changing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
could I change?
could you change?
could she change?
could we change?
could you change?
could they change? 	could I be changing?
could you be changing?
could she be changing?
could we be changing?
could you be changing?
could they be changing? 	could I have changed?
could you have changed?
could she have changed?
could we have changed?
could you have changed?
could they have changed? 	could I have been changing?
could you have been changing?
could she have been changing?
could we have been changing?
could you have been changing?
could they have been changing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
couldn't I change?
couldn't you change?
couldn't she change?
couldn't we change?
couldn't you change?
couldn't they change? 	couldn't I be changing?
couldn't you be changing?
couldn't she be changing?
couldn't we be changing?
couldn't you be changing?
couldn't they be changing? 	couldn't I have changed?
couldn't you have changed?
couldn't she have changed?
couldn't we have changed?
couldn't you have changed?
couldn't they have changed? 	couldn't I have been changing?
couldn't you have been changing?
couldn't she have been changing?
couldn't we have been changing?
couldn't you have been changing?
couldn't they have been changing?