could ring
Irregular verb: ring - rang- rung

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could ring
you could ring
he could ring
we could ring
you could ring
they could ring 	I could be ringing
you could be ringing
he could be ringing
we could be ringing
you could be ringing
they could be ringing	I could have rung
you could have rung
he could have rung
we could have rung
you could have rung
they could have rung	I could have been ringing
you could have been ringing
he could have been ringing
we could have been ringing
you could have been ringing
they could have been ringing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't ring
you couldn't ring
he couldn't ring
we couldn't ring
you couldn't ring
they couldn't ring 	I couldn't be ringing
you couldn't be ringing
he couldn't be ringing
we couldn't be ringing
you couldn't be ringing
they couldn't be ringing	I couldn't have rung
you couldn't have rung
he couldn't have rung
we couldn't have rung
you couldn't have rung
they couldn't have rung	I couldn't have been ringing
you couldn't have been ringing
he couldn't have been ringing
we couldn't have been ringing
you couldn't have been ringing
they couldn't have been ringing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I ring?
could you ring?
could he ring?
could we ring?
could you ring?
could they ring? 	could I be ringing?
could you be ringing?
could he be ringing?
could we be ringing?
could you be ringing?
could they be ringing? 	could I have rung?
could you have rung?
could he have rung?
could we have rung?
could you have rung?
could they have rung? 	could I have been ringing?
could you have been ringing?
could he have been ringing?
could we have been ringing?
could you have been ringing?
could they have been ringing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I ring?
couldn't you ring?
couldn't he ring?
couldn't we ring?
couldn't you ring?
couldn't they ring? 	couldn't I be ringing?
couldn't you be ringing?
couldn't he be ringing?
couldn't we be ringing?
couldn't you be ringing?
couldn't they be ringing? 	couldn't I have rung?
couldn't you have rung?
couldn't he have rung?
couldn't we have rung?
couldn't you have rung?
couldn't they have rung? 	couldn't I have been ringing?
couldn't you have been ringing?
couldn't he have been ringing?
couldn't we have been ringing?
couldn't you have been ringing?
couldn't they have been ringing?