I could quarrel you could quarrel she could quarrel we could quarrel you could quarrel they could quarrel
V-ing form
I could be quarrelling you could be quarrelling she could be quarrelling we could be quarrelling you could be quarrelling they could be quarrelling
Perfect
I could have quarrelled you could have quarrelled she could have quarrelled we could have quarrelled you could have quarrelled they could have quarrelled
V-ing perfect
I could have been quarrelling you could have been quarrelling she could have been quarrelling we could have been quarrelling you could have been quarrelling they could have been quarrelling
Negation
Simple form
I could not quarrel you could not quarrel she could not quarrel we could not quarrel you could not quarrel they could not quarrel
V-ing form
I could not be quarrelling you could not be quarrelling she could not be quarrelling we could not be quarrelling you could not be quarrelling they could not be quarrelling
Perfect
I could not have quarrelled you could not have quarrelled she could not have quarrelled we could not have quarrelled you could not have quarrelled they could not have quarrelled
V-ing perfect
I could not have been quarrelling you could not have been quarrelling she could not have been quarrelling we could not have been quarrelling you could not have been quarrelling they could not have been quarrelling
Interrogative form
Simple form
could I quarrel? could you quarrel? could she quarrel? could we quarrel? could you quarrel? could they quarrel?
V-ing form
could I be quarrelling? could you be quarrelling? could she be quarrelling? could we be quarrelling? could you be quarrelling? could they be quarrelling?
Perfect
could I have quarrelled? could you have quarrelled? could she have quarrelled? could we have quarrelled? could you have quarrelled? could they have quarrelled?
V-ing perfect
could I have been quarrelling? could you have been quarrelling? could she have been quarrelling? could we have been quarrelling? could you have been quarrelling? could they have been quarrelling?
Interro-negative form
Simple form
could I not quarrel? could you not quarrel? could she not quarrel? could we not quarrel? could you not quarrel? could they not quarrel?
V-ing form
could I not be quarrelling? could you not be quarrelling? could she not be quarrelling? could we not be quarrelling? could you not be quarrelling? could they not be quarrelling?
Perfect
could I not have quarrelled? could you not have quarrelled? could she not have quarrelled? could we not have quarrelled? could you not have quarrelled? could they not have quarrelled?
V-ing perfect
could I not have been quarrelling? could you not have been quarrelling? could she not have been quarrelling? could we not have been quarrelling? could you not have been quarrelling? could they not have been quarrelling?