I could dab you could dab she could dab we could dab you could dab they could dab
V-ing form
I could be dabbing you could be dabbing she could be dabbing we could be dabbing you could be dabbing they could be dabbing
Perfect
I could have dabbed you could have dabbed she could have dabbed we could have dabbed you could have dabbed they could have dabbed
V-ing perfect
I could have been dabbing you could have been dabbing she could have been dabbing we could have been dabbing you could have been dabbing they could have been dabbing
Negation
Simple form
I could not dab you could not dab she could not dab we could not dab you could not dab they could not dab
V-ing form
I could not be dabbing you could not be dabbing she could not be dabbing we could not be dabbing you could not be dabbing they could not be dabbing
Perfect
I could not have dabbed you could not have dabbed she could not have dabbed we could not have dabbed you could not have dabbed they could not have dabbed
V-ing perfect
I could not have been dabbing you could not have been dabbing she could not have been dabbing we could not have been dabbing you could not have been dabbing they could not have been dabbing
Interrogative form
Simple form
could I dab? could you dab? could she dab? could we dab? could you dab? could they dab?
V-ing form
could I be dabbing? could you be dabbing? could she be dabbing? could we be dabbing? could you be dabbing? could they be dabbing?
Perfect
could I have dabbed? could you have dabbed? could she have dabbed? could we have dabbed? could you have dabbed? could they have dabbed?
V-ing perfect
could I have been dabbing? could you have been dabbing? could she have been dabbing? could we have been dabbing? could you have been dabbing? could they have been dabbing?
Interro-negative form
Simple form
could I not dab? could you not dab? could she not dab? could we not dab? could you not dab? could they not dab?
V-ing form
could I not be dabbing? could you not be dabbing? could she not be dabbing? could we not be dabbing? could you not be dabbing? could they not be dabbing?
Perfect
could I not have dabbed? could you not have dabbed? could she not have dabbed? could we not have dabbed? could you not have dabbed? could they not have dabbed?
V-ing perfect
could I not have been dabbing? could you not have been dabbing? could she not have been dabbing? could we not have been dabbing? could you not have been dabbing? could they not have been dabbing?