English verb conjugation
COULD TREPHINE

Regular verb: trephine - trephined - trephined

Affirmation

Simple form	V-ing form
I could trephine you could trephine he could trephine we could trephine you could trephine they could trephine	I could be trephining you could be trephining he could be trephining we could be trephining you could be trephining they could be trephining
Perfect	V-ing perfect
I could have trephined you could have trephined he could have trephined we could have trephined you could have trephined they could have trephined	I could have been trephining you could have been trephining he could have been trephining we could have been trephining you could have been trephining they could have been trephining

Negation

Simple form	V-ing form
I could not trephine you could not trephine he could not trephine we could not trephine you could not trephine they could not trephine	I could not be trephining you could not be trephining he could not be trephining we could not be trephining you could not be trephining they could not be trephining
Perfect	V-ing perfect
I could not have trephined you could not have trephined he could not have trephined we could not have trephined you could not have trephined they could not have trephined	I could not have been trephining you could not have been trephining he could not have been trephining we could not have been trephining you could not have been trephining they could not have been trephining

Interrogative form

Simple form	V-ing form
could I trephine? could you trephine? could he trephine? could we trephine? could you trephine? could they trephine?	could I be trephining? could you be trephining? could he be trephining? could we be trephining? could you be trephining? could they be trephining?
Perfect	V-ing perfect
could I have trephined? could you have trephined? could he have trephined? could we have trephined? could you have trephined? could they have trephined?	could I have been trephining? could you have been trephining? could he have been trephining? could we have been trephining? could you have been trephining? could they have been trephining?

Interro-negative form

Simple form	V-ing form
could I not trephine? could you not trephine? could he not trephine? could we not trephine? could you not trephine? could they not trephine?	could I not be trephining? could you not be trephining? could he not be trephining? could we not be trephining? could you not be trephining? could they not be trephining?
Perfect	V-ing perfect
could I not have trephined? could you not have trephined? could he not have trephined? could we not have trephined? could you not have trephined? could they not have trephined?	could I not have been trephining? could you not have been trephining? could he not have been trephining? could we not have been trephining? could you not have been trephining? could they not have been trephining?