I could tambour you could tambour he could tambour we could tambour you could tambour they could tambour
V-ing form
I could be tambouring you could be tambouring he could be tambouring we could be tambouring you could be tambouring they could be tambouring
Perfect
I could have tamboured you could have tamboured he could have tamboured we could have tamboured you could have tamboured they could have tamboured
V-ing perfect
I could have been tambouring you could have been tambouring he could have been tambouring we could have been tambouring you could have been tambouring they could have been tambouring
Negation
Simple form
I could not tambour you could not tambour he could not tambour we could not tambour you could not tambour they could not tambour
V-ing form
I could not be tambouring you could not be tambouring he could not be tambouring we could not be tambouring you could not be tambouring they could not be tambouring
Perfect
I could not have tamboured you could not have tamboured he could not have tamboured we could not have tamboured you could not have tamboured they could not have tamboured
V-ing perfect
I could not have been tambouring you could not have been tambouring he could not have been tambouring we could not have been tambouring you could not have been tambouring they could not have been tambouring
Interrogative form
Simple form
could I tambour? could you tambour? could he tambour? could we tambour? could you tambour? could they tambour?
V-ing form
could I be tambouring? could you be tambouring? could he be tambouring? could we be tambouring? could you be tambouring? could they be tambouring?
Perfect
could I have tamboured? could you have tamboured? could he have tamboured? could we have tamboured? could you have tamboured? could they have tamboured?
V-ing perfect
could I have been tambouring? could you have been tambouring? could he have been tambouring? could we have been tambouring? could you have been tambouring? could they have been tambouring?
Interro-negative form
Simple form
could I not tambour? could you not tambour? could he not tambour? could we not tambour? could you not tambour? could they not tambour?
V-ing form
could I not be tambouring? could you not be tambouring? could he not be tambouring? could we not be tambouring? could you not be tambouring? could they not be tambouring?
Perfect
could I not have tamboured? could you not have tamboured? could he not have tamboured? could we not have tamboured? could you not have tamboured? could they not have tamboured?
V-ing perfect
could I not have been tambouring? could you not have been tambouring? could he not have been tambouring? could we not have been tambouring? could you not have been tambouring? could they not have been tambouring?