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
she could diphthongise
we could diphthongise
you could diphthongise
they could diphthongise 	I could be diphthongising
you could be diphthongising
she could be diphthongising
we could be diphthongising
you could be diphthongising
they could be diphthongising	I could have diphthongised
you could have diphthongised
she 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
she 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 could not diphthongise
you could not diphthongise
she could not diphthongise
we could not diphthongise
you could not diphthongise
they could not diphthongise 	I could not be diphthongising
you could not be diphthongising
she could not be diphthongising
we could not be diphthongising
you could not be diphthongising
they could not be diphthongising	I could not have diphthongised
you could not have diphthongised
she could not have diphthongised
we could not have diphthongised
you could not have diphthongised
they could not have diphthongised	I could not have been diphthongising
you could not have been diphthongising
she could not have been diphthongising
we could not have been diphthongising
you could not have been diphthongising
they could not have been diphthongising	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
could I diphthongise?
could you diphthongise?
could she diphthongise?
could we diphthongise?
could you diphthongise?
could they diphthongise? 	could I be diphthongising?
could you be diphthongising?
could she be diphthongising?
could we be diphthongising?
could you be diphthongising?
could they be diphthongising? 	could I have diphthongised?
could you have diphthongised?
could she 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 she 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 	
could I not diphthongise?
could you not diphthongise?
could she not diphthongise?
could we not diphthongise?
could you not diphthongise?
could they not diphthongise? 	could I not be diphthongising?
could you not be diphthongising?
could she not be diphthongising?
could we not be diphthongising?
could you not be diphthongising?
could they not be diphthongising? 	could I not have diphthongised?
could you not have diphthongised?
could she not have diphthongised?
could we not have diphthongised?
could you not have diphthongised?
could they not have diphthongised? 	could I not have been diphthongising?
could you not have been diphthongising?
could she not have been diphthongising?
could we not have been diphthongising?
could you not have been diphthongising?
could they not have been diphthongising?