I can sour you can sour he can sour we can sour you can sour they can sour
V-ing form
I can be souring you can be souring he can be souring we can be souring you can be souring they can be souring
Perfect
I can have soured you can have soured he can have soured we can have soured you can have soured they can have soured
V-ing perfect
I can have been souring you can have been souring he can have been souring we can have been souring you can have been souring they can have been souring
Negation
Simple form
I cannot sour you cannot sour he cannot sour we cannot sour you cannot sour they cannot sour
V-ing form
I cannot be souring you cannot be souring he cannot be souring we cannot be souring you cannot be souring they cannot be souring
Perfect
I cannot have soured you cannot have soured he cannot have soured we cannot have soured you cannot have soured they cannot have soured
V-ing perfect
I cannot have been souring you cannot have been souring he cannot have been souring we cannot have been souring you cannot have been souring they cannot have been souring
Interrogative form
Simple form
can I sour? can you sour? can he sour? can we sour? can you sour? can they sour?
V-ing form
can I be souring? can you be souring? can he be souring? can we be souring? can you be souring? can they be souring?
Perfect
can I have soured? can you have soured? can he have soured? can we have soured? can you have soured? can they have soured?
V-ing perfect
can I have been souring? can you have been souring? can he have been souring? can we have been souring? can you have been souring? can they have been souring?
Interro-negative form
Simple form
can I not sour? can you not sour? can he not sour? can we not sour? can you not sour? can they not sour?
V-ing form
can I not be souring? can you not be souring? can he not be souring? can we not be souring? can you not be souring? can they not be souring?
Perfect
can I not have soured? can you not have soured? can he not have soured? can we not have soured? can you not have soured? can they not have soured?
V-ing perfect
can I not have been souring? can you not have been souring? can he not have been souring? can we not have been souring? can you not have been souring? can they not have been souring?