I can sum you can sum he can sum we can sum you can sum they can sum
Forma con V-ing
I can be summing you can be summing he can be summing we can be summing you can be summing they can be summing
Perfecto
I can have summed you can have summed he can have summed we can have summed you can have summed they can have summed
Perfecto con V-ing
I can have been summing you can have been summing he can have been summing we can have been summing you can have been summing they can have been summing
Negación
Forma simple
I can't sum you can't sum he can't sum we can't sum you can't sum they can't sum
Forma con V-ing
I can't be summing you can't be summing he can't be summing we can't be summing you can't be summing they can't be summing
Perfecto
I can't have summed you can't have summed he can't have summed we can't have summed you can't have summed they can't have summed
Perfecto con V-ing
I can't have been summing you can't have been summing he can't have been summing we can't have been summing you can't have been summing they can't have been summing
Forma interrogativa
Forma simple
can I sum? can you sum? can he sum? can we sum? can you sum? can they sum?
Forma con V-ing
can I be summing? can you be summing? can he be summing? can we be summing? can you be summing? can they be summing?
Perfecto
can I have summed? can you have summed? can he have summed? can we have summed? can you have summed? can they have summed?
Perfecto con V-ing
can I have been summing? can you have been summing? can he have been summing? can we have been summing? can you have been summing? can they have been summing?
Forma interro-negativa
Forma simple
can't I sum? can't you sum? can't he sum? can't we sum? can't you sum? can't they sum?
Forma con V-ing
can't I be summing? can't you be summing? can't he be summing? can't we be summing? can't you be summing? can't they be summing?
Perfecto
can't I have summed? can't you have summed? can't he have summed? can't we have summed? can't you have summed? can't they have summed?
Perfecto con V-ing
can't I have been summing? can't you have been summing? can't he have been summing? can't we have been summing? can't you have been summing? can't they have been summing?