I could bestir you could bestir he could bestir we could bestir you could bestir they could bestir
V-ing form
I could be bestirring you could be bestirring he could be bestirring we could be bestirring you could be bestirring they could be bestirring
Perfect
I could have bestirred you could have bestirred he could have bestirred we could have bestirred you could have bestirred they could have bestirred
V-ing perfect
I could have been bestirring you could have been bestirring he could have been bestirring we could have been bestirring you could have been bestirring they could have been bestirring
Negation
Simple form
I could not bestir you could not bestir he could not bestir we could not bestir you could not bestir they could not bestir
V-ing form
I could not be bestirring you could not be bestirring he could not be bestirring we could not be bestirring you could not be bestirring they could not be bestirring
Perfect
I could not have bestirred you could not have bestirred he could not have bestirred we could not have bestirred you could not have bestirred they could not have bestirred
V-ing perfect
I could not have been bestirring you could not have been bestirring he could not have been bestirring we could not have been bestirring you could not have been bestirring they could not have been bestirring
Interrogative form
Simple form
could I bestir? could you bestir? could he bestir? could we bestir? could you bestir? could they bestir?
V-ing form
could I be bestirring? could you be bestirring? could he be bestirring? could we be bestirring? could you be bestirring? could they be bestirring?
Perfect
could I have bestirred? could you have bestirred? could he have bestirred? could we have bestirred? could you have bestirred? could they have bestirred?
V-ing perfect
could I have been bestirring? could you have been bestirring? could he have been bestirring? could we have been bestirring? could you have been bestirring? could they have been bestirring?
Interro-negative form
Simple form
could I not bestir? could you not bestir? could he not bestir? could we not bestir? could you not bestir? could they not bestir?
V-ing form
could I not be bestirring? could you not be bestirring? could he not be bestirring? could we not be bestirring? could you not be bestirring? could they not be bestirring?
Perfect
could I not have bestirred? could you not have bestirred? could he not have bestirred? could we not have bestirred? could you not have bestirred? could they not have bestirred?
V-ing perfect
could I not have been bestirring? could you not have been bestirring? could he not have been bestirring? could we not have been bestirring? could you not have been bestirring? could they not have been bestirring?