I could zigzag you could zigzag he could zigzag we could zigzag you could zigzag they could zigzag
V-ing form
I could be zigzagging you could be zigzagging he could be zigzagging we could be zigzagging you could be zigzagging they could be zigzagging
Perfect
I could have zigzagged you could have zigzagged he could have zigzagged we could have zigzagged you could have zigzagged they could have zigzagged
V-ing perfect
I could have been zigzagging you could have been zigzagging he could have been zigzagging we could have been zigzagging you could have been zigzagging they could have been zigzagging
Negation
Simple form
I could not zigzag you could not zigzag he could not zigzag we could not zigzag you could not zigzag they could not zigzag
V-ing form
I could not be zigzagging you could not be zigzagging he could not be zigzagging we could not be zigzagging you could not be zigzagging they could not be zigzagging
Perfect
I could not have zigzagged you could not have zigzagged he could not have zigzagged we could not have zigzagged you could not have zigzagged they could not have zigzagged
V-ing perfect
I could not have been zigzagging you could not have been zigzagging he could not have been zigzagging we could not have been zigzagging you could not have been zigzagging they could not have been zigzagging
Interrogative form
Simple form
could I zigzag? could you zigzag? could he zigzag? could we zigzag? could you zigzag? could they zigzag?
V-ing form
could I be zigzagging? could you be zigzagging? could he be zigzagging? could we be zigzagging? could you be zigzagging? could they be zigzagging?
Perfect
could I have zigzagged? could you have zigzagged? could he have zigzagged? could we have zigzagged? could you have zigzagged? could they have zigzagged?
V-ing perfect
could I have been zigzagging? could you have been zigzagging? could he have been zigzagging? could we have been zigzagging? could you have been zigzagging? could they have been zigzagging?
Interro-negative form
Simple form
could I not zigzag? could you not zigzag? could he not zigzag? could we not zigzag? could you not zigzag? could they not zigzag?
V-ing form
could I not be zigzagging? could you not be zigzagging? could he not be zigzagging? could we not be zigzagging? could you not be zigzagging? could they not be zigzagging?
Perfect
could I not have zigzagged? could you not have zigzagged? could he not have zigzagged? could we not have zigzagged? could you not have zigzagged? could they not have zigzagged?
V-ing perfect
could I not have been zigzagging? could you not have been zigzagging? could he not have been zigzagging? could we not have been zigzagging? could you not have been zigzagging? could they not have been zigzagging?