I can stock you can stock he can stock we can stock you can stock they can stock
V-ing form
I can be stocking you can be stocking he can be stocking we can be stocking you can be stocking they can be stocking
Perfect
I can have stocked you can have stocked he can have stocked we can have stocked you can have stocked they can have stocked
V-ing perfect
I can have been stocking you can have been stocking he can have been stocking we can have been stocking you can have been stocking they can have been stocking
Negation
Simple form
I cannot stock you cannot stock he cannot stock we cannot stock you cannot stock they cannot stock
V-ing form
I cannot be stocking you cannot be stocking he cannot be stocking we cannot be stocking you cannot be stocking they cannot be stocking
Perfect
I cannot have stocked you cannot have stocked he cannot have stocked we cannot have stocked you cannot have stocked they cannot have stocked
V-ing perfect
I cannot have been stocking you cannot have been stocking he cannot have been stocking we cannot have been stocking you cannot have been stocking they cannot have been stocking
Interrogative form
Simple form
can I stock? can you stock? can he stock? can we stock? can you stock? can they stock?
V-ing form
can I be stocking? can you be stocking? can he be stocking? can we be stocking? can you be stocking? can they be stocking?
Perfect
can I have stocked? can you have stocked? can he have stocked? can we have stocked? can you have stocked? can they have stocked?
V-ing perfect
can I have been stocking? can you have been stocking? can he have been stocking? can we have been stocking? can you have been stocking? can they have been stocking?
Interro-negative form
Simple form
can I not stock? can you not stock? can he not stock? can we not stock? can you not stock? can they not stock?
V-ing form
can I not be stocking? can you not be stocking? can he not be stocking? can we not be stocking? can you not be stocking? can they not be stocking?
Perfect
can I not have stocked? can you not have stocked? can he not have stocked? can we not have stocked? can you not have stocked? can they not have stocked?
V-ing perfect
can I not have been stocking? can you not have been stocking? can he not have been stocking? can we not have been stocking? can you not have been stocking? can they not have been stocking?