I could bog you could bog he could bog we could bog you could bog they could bog
V-ing form
I could be bogging you could be bogging he could be bogging we could be bogging you could be bogging they could be bogging
Perfect
I could have bogged you could have bogged he could have bogged we could have bogged you could have bogged they could have bogged
V-ing perfect
I could have been bogging you could have been bogging he could have been bogging we could have been bogging you could have been bogging they could have been bogging
Negation
Simple form
I could not bog you could not bog he could not bog we could not bog you could not bog they could not bog
V-ing form
I could not be bogging you could not be bogging he could not be bogging we could not be bogging you could not be bogging they could not be bogging
Perfect
I could not have bogged you could not have bogged he could not have bogged we could not have bogged you could not have bogged they could not have bogged
V-ing perfect
I could not have been bogging you could not have been bogging he could not have been bogging we could not have been bogging you could not have been bogging they could not have been bogging
Interrogative form
Simple form
could I bog? could you bog? could he bog? could we bog? could you bog? could they bog?
V-ing form
could I be bogging? could you be bogging? could he be bogging? could we be bogging? could you be bogging? could they be bogging?
Perfect
could I have bogged? could you have bogged? could he have bogged? could we have bogged? could you have bogged? could they have bogged?
V-ing perfect
could I have been bogging? could you have been bogging? could he have been bogging? could we have been bogging? could you have been bogging? could they have been bogging?
Interro-negative form
Simple form
could I not bog? could you not bog? could he not bog? could we not bog? could you not bog? could they not bog?
V-ing form
could I not be bogging? could you not be bogging? could he not be bogging? could we not be bogging? could you not be bogging? could they not be bogging?
Perfect
could I not have bogged? could you not have bogged? could he not have bogged? could we not have bogged? could you not have bogged? could they not have bogged?
V-ing perfect
could I not have been bogging? could you not have been bogging? could he not have been bogging? could we not have been bogging? could you not have been bogging? could they not have been bogging?