I could query you could query he could query we could query you could query they could query
V-ing form
I could be querying you could be querying he could be querying we could be querying you could be querying they could be querying
Perfect
I could have queried you could have queried he could have queried we could have queried you could have queried they could have queried
V-ing perfect
I could have been querying you could have been querying he could have been querying we could have been querying you could have been querying they could have been querying
Negation
Simple form
I could not query you could not query he could not query we could not query you could not query they could not query
V-ing form
I could not be querying you could not be querying he could not be querying we could not be querying you could not be querying they could not be querying
Perfect
I could not have queried you could not have queried he could not have queried we could not have queried you could not have queried they could not have queried
V-ing perfect
I could not have been querying you could not have been querying he could not have been querying we could not have been querying you could not have been querying they could not have been querying
Interrogative form
Simple form
could I query? could you query? could he query? could we query? could you query? could they query?
V-ing form
could I be querying? could you be querying? could he be querying? could we be querying? could you be querying? could they be querying?
Perfect
could I have queried? could you have queried? could he have queried? could we have queried? could you have queried? could they have queried?
V-ing perfect
could I have been querying? could you have been querying? could he have been querying? could we have been querying? could you have been querying? could they have been querying?
Interro-negative form
Simple form
could I not query? could you not query? could he not query? could we not query? could you not query? could they not query?
V-ing form
could I not be querying? could you not be querying? could he not be querying? could we not be querying? could you not be querying? could they not be querying?
Perfect
could I not have queried? could you not have queried? could he not have queried? could we not have queried? could you not have queried? could they not have queried?
V-ing perfect
could I not have been querying? could you not have been querying? could he not have been querying? could we not have been querying? could you not have been querying? could they not have been querying?