I can sweeten you can sweeten she can sweeten we can sweeten you can sweeten they can sweeten
V-ing form
I can be sweetening you can be sweetening she can be sweetening we can be sweetening you can be sweetening they can be sweetening
Perfect
I can have sweetened you can have sweetened she can have sweetened we can have sweetened you can have sweetened they can have sweetened
V-ing perfect
I can have been sweetening you can have been sweetening she can have been sweetening we can have been sweetening you can have been sweetening they can have been sweetening
Negation
Simple form
I cannot sweeten you cannot sweeten she cannot sweeten we cannot sweeten you cannot sweeten they cannot sweeten
V-ing form
I cannot be sweetening you cannot be sweetening she cannot be sweetening we cannot be sweetening you cannot be sweetening they cannot be sweetening
Perfect
I cannot have sweetened you cannot have sweetened she cannot have sweetened we cannot have sweetened you cannot have sweetened they cannot have sweetened
V-ing perfect
I cannot have been sweetening you cannot have been sweetening she cannot have been sweetening we cannot have been sweetening you cannot have been sweetening they cannot have been sweetening
Interrogative form
Simple form
can I sweeten? can you sweeten? can she sweeten? can we sweeten? can you sweeten? can they sweeten?
V-ing form
can I be sweetening? can you be sweetening? can she be sweetening? can we be sweetening? can you be sweetening? can they be sweetening?
Perfect
can I have sweetened? can you have sweetened? can she have sweetened? can we have sweetened? can you have sweetened? can they have sweetened?
V-ing perfect
can I have been sweetening? can you have been sweetening? can she have been sweetening? can we have been sweetening? can you have been sweetening? can they have been sweetening?
Interro-negative form
Simple form
can I not sweeten? can you not sweeten? can she not sweeten? can we not sweeten? can you not sweeten? can they not sweeten?
V-ing form
can I not be sweetening? can you not be sweetening? can she not be sweetening? can we not be sweetening? can you not be sweetening? can they not be sweetening?
Perfect
can I not have sweetened? can you not have sweetened? can she not have sweetened? can we not have sweetened? can you not have sweetened? can they not have sweetened?
V-ing perfect
can I not have been sweetening? can you not have been sweetening? can she not have been sweetening? can we not have been sweetening? can you not have been sweetening? can they not have been sweetening?