could diphthongise
Verbe régulier : diphthongise - diphthongised- diphthongised

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I could diphthongise
you could diphthongise
he could diphthongise
we could diphthongise
you could diphthongise
they could diphthongise 	I could be diphthongising
you could be diphthongising
he could be diphthongising
we could be diphthongising
you could be diphthongising
they could be diphthongising	I could have diphthongised
you could have diphthongised
he could have diphthongised
we could have diphthongised
you could have diphthongised
they could have diphthongised	I could have been diphthongising
you could have been diphthongising
he could have been diphthongising
we could have been diphthongising
you could have been diphthongising
they could have been diphthongising	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I couldn't diphthongise
you couldn't diphthongise
he couldn't diphthongise
we couldn't diphthongise
you couldn't diphthongise
they couldn't diphthongise 	I couldn't be diphthongising
you couldn't be diphthongising
he couldn't be diphthongising
we couldn't be diphthongising
you couldn't be diphthongising
they couldn't be diphthongising	I couldn't have diphthongised
you couldn't have diphthongised
he couldn't have diphthongised
we couldn't have diphthongised
you couldn't have diphthongised
they couldn't have diphthongised	I couldn't have been diphthongising
you couldn't have been diphthongising
he couldn't have been diphthongising
we couldn't have been diphthongising
you couldn't have been diphthongising
they couldn't have been diphthongising	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
could I diphthongise?
could you diphthongise?
could he diphthongise?
could we diphthongise?
could you diphthongise?
could they diphthongise? 	could I be diphthongising?
could you be diphthongising?
could he be diphthongising?
could we be diphthongising?
could you be diphthongising?
could they be diphthongising? 	could I have diphthongised?
could you have diphthongised?
could he have diphthongised?
could we have diphthongised?
could you have diphthongised?
could they have diphthongised? 	could I have been diphthongising?
could you have been diphthongising?
could he have been diphthongising?
could we have been diphthongising?
could you have been diphthongising?
could they have been diphthongising? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
couldn't I diphthongise?
couldn't you diphthongise?
couldn't he diphthongise?
couldn't we diphthongise?
couldn't you diphthongise?
couldn't they diphthongise? 	couldn't I be diphthongising?
couldn't you be diphthongising?
couldn't he be diphthongising?
couldn't we be diphthongising?
couldn't you be diphthongising?
couldn't they be diphthongising? 	couldn't I have diphthongised?
couldn't you have diphthongised?
couldn't he have diphthongised?
couldn't we have diphthongised?
couldn't you have diphthongised?
couldn't they have diphthongised? 	couldn't I have been diphthongising?
couldn't you have been diphthongising?
couldn't he have been diphthongising?
couldn't we have been diphthongising?
couldn't you have been diphthongising?
couldn't they have been diphthongising?