English verb conjugation
COULD RING

Irregular verb: ring - rang - rung

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?