I can sweeten you can sweeten he can sweeten we can sweeten you can sweeten they can sweeten
V-ing form
I can be sweetening you can be sweetening he can be sweetening we can be sweetening you can be sweetening they can be sweetening
Perfect
I can have sweetened you can have sweetened he 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 he can have been sweetening we can have been sweetening you can have been sweetening they can have been sweetening
Negation
Simple form
I can't sweeten you can't sweeten he can't sweeten we can't sweeten you can't sweeten they can't sweeten
V-ing form
I can't be sweetening you can't be sweetening he can't be sweetening we can't be sweetening you can't be sweetening they can't be sweetening
Perfect
I can't have sweetened you can't have sweetened he can't have sweetened we can't have sweetened you can't have sweetened they can't have sweetened
V-ing perfect
I can't have been sweetening you can't have been sweetening he can't have been sweetening we can't have been sweetening you can't have been sweetening they can't have been sweetening
Interrogative form
Simple form
can I sweeten? can you sweeten? can he sweeten? can we sweeten? can you sweeten? can they sweeten?
V-ing form
can I be sweetening? can you be sweetening? can he be sweetening? can we be sweetening? can you be sweetening? can they be sweetening?
Perfect
can I have sweetened? can you have sweetened? can he 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 he have been sweetening? can we have been sweetening? can you have been sweetening? can they have been sweetening?
Interro-negative form
Simple form
can't I sweeten? can't you sweeten? can't he sweeten? can't we sweeten? can't you sweeten? can't they sweeten?
V-ing form
can't I be sweetening? can't you be sweetening? can't he be sweetening? can't we be sweetening? can't you be sweetening? can't they be sweetening?
Perfect
can't I have sweetened? can't you have sweetened? can't he have sweetened? can't we have sweetened? can't you have sweetened? can't they have sweetened?
V-ing perfect
can't I have been sweetening? can't you have been sweetening? can't he have been sweetening? can't we have been sweetening? can't you have been sweetening? can't they have been sweetening?