English verb conjugation
COULD BOOK

Regular verb: book - booked - booked

Affirmation

Simple form	V-ing form
I could book you could book he could book we could book you could book they could book	I could be booking you could be booking he could be booking we could be booking you could be booking they could be booking
Perfect	V-ing perfect
I could have booked you could have booked he could have booked we could have booked you could have booked they could have booked	I could have been booking you could have been booking he could have been booking we could have been booking you could have been booking they could have been booking

Negation

Simple form	V-ing form
I could not book you could not book he could not book we could not book you could not book they could not book	I could not be booking you could not be booking he could not be booking we could not be booking you could not be booking they could not be booking
Perfect	V-ing perfect
I could not have booked you could not have booked he could not have booked we could not have booked you could not have booked they could not have booked	I could not have been booking you could not have been booking he could not have been booking we could not have been booking you could not have been booking they could not have been booking

Interrogative form

Simple form	V-ing form
could I book? could you book? could he book? could we book? could you book? could they book?	could I be booking? could you be booking? could he be booking? could we be booking? could you be booking? could they be booking?
Perfect	V-ing perfect
could I have booked? could you have booked? could he have booked? could we have booked? could you have booked? could they have booked?	could I have been booking? could you have been booking? could he have been booking? could we have been booking? could you have been booking? could they have been booking?

Interro-negative form

Simple form	V-ing form
could I not book? could you not book? could he not book? could we not book? could you not book? could they not book?	could I not be booking? could you not be booking? could he not be booking? could we not be booking? could you not be booking? could they not be booking?
Perfect	V-ing perfect
could I not have booked? could you not have booked? could he not have booked? could we not have booked? could you not have booked? could they not have booked?	could I not have been booking? could you not have been booking? could he not have been booking? could we not have been booking? could you not have been booking? could they not have been booking?