English verb conjugation
COULD MAST

Regular verb: mast - masted - masted

Affirmation

Simple form	V-ing form
I could mast you could mast he could mast we could mast you could mast they could mast	I could be masting you could be masting he could be masting we could be masting you could be masting they could be masting
Perfect	V-ing perfect
I could have masted you could have masted he could have masted we could have masted you could have masted they could have masted	I could have been masting you could have been masting he could have been masting we could have been masting you could have been masting they could have been masting

Negation

Simple form	V-ing form
I could not mast you could not mast he could not mast we could not mast you could not mast they could not mast	I could not be masting you could not be masting he could not be masting we could not be masting you could not be masting they could not be masting
Perfect	V-ing perfect
I could not have masted you could not have masted he could not have masted we could not have masted you could not have masted they could not have masted	I could not have been masting you could not have been masting he could not have been masting we could not have been masting you could not have been masting they could not have been masting

Interrogative form

Simple form	V-ing form
could I mast? could you mast? could he mast? could we mast? could you mast? could they mast?	could I be masting? could you be masting? could he be masting? could we be masting? could you be masting? could they be masting?
Perfect	V-ing perfect
could I have masted? could you have masted? could he have masted? could we have masted? could you have masted? could they have masted?	could I have been masting? could you have been masting? could he have been masting? could we have been masting? could you have been masting? could they have been masting?

Interro-negative form

Simple form	V-ing form
could I not mast? could you not mast? could he not mast? could we not mast? could you not mast? could they not mast?	could I not be masting? could you not be masting? could he not be masting? could we not be masting? could you not be masting? could they not be masting?
Perfect	V-ing perfect
could I not have masted? could you not have masted? could he not have masted? could we not have masted? could you not have masted? could they not have masted?	could I not have been masting? could you not have been masting? could he not have been masting? could we not have been masting? could you not have been masting? could they not have been masting?