I could supple you could supple he could supple we could supple you could supple they could supple
V-ing form
I could be suppling you could be suppling he could be suppling we could be suppling you could be suppling they could be suppling
Perfect
I could have suppled you could have suppled he could have suppled we could have suppled you could have suppled they could have suppled
V-ing perfect
I could have been suppling you could have been suppling he could have been suppling we could have been suppling you could have been suppling they could have been suppling
Negation
Simple form
I could not supple you could not supple he could not supple we could not supple you could not supple they could not supple
V-ing form
I could not be suppling you could not be suppling he could not be suppling we could not be suppling you could not be suppling they could not be suppling
Perfect
I could not have suppled you could not have suppled he could not have suppled we could not have suppled you could not have suppled they could not have suppled
V-ing perfect
I could not have been suppling you could not have been suppling he could not have been suppling we could not have been suppling you could not have been suppling they could not have been suppling
Interrogative form
Simple form
could I supple? could you supple? could he supple? could we supple? could you supple? could they supple?
V-ing form
could I be suppling? could you be suppling? could he be suppling? could we be suppling? could you be suppling? could they be suppling?
Perfect
could I have suppled? could you have suppled? could he have suppled? could we have suppled? could you have suppled? could they have suppled?
V-ing perfect
could I have been suppling? could you have been suppling? could he have been suppling? could we have been suppling? could you have been suppling? could they have been suppling?
Interro-negative form
Simple form
could I not supple? could you not supple? could he not supple? could we not supple? could you not supple? could they not supple?
V-ing form
could I not be suppling? could you not be suppling? could he not be suppling? could we not be suppling? could you not be suppling? could they not be suppling?
Perfect
could I not have suppled? could you not have suppled? could he not have suppled? could we not have suppled? could you not have suppled? could they not have suppled?
V-ing perfect
could I not have been suppling? could you not have been suppling? could he not have been suppling? could we not have been suppling? could you not have been suppling? could they not have been suppling?