Conjugación del verbo inglés
CAN SUM

Verbo regular: sum - summed - summed

Afirmación

Forma simple	Forma con V-ing
I can sum you can sum he can sum we can sum you can sum they can sum	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	Perfecto con V-ing
I can have summed you can have summed he can have summed we can have summed you can have summed they can have summed	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	Forma con V-ing
I can't sum you can't sum he can't sum we can't sum you can't sum they can't sum	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	Perfecto con V-ing
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	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	Forma con V-ing
can I sum? can you sum? can he sum? can we sum? can you sum? can they sum?	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	Perfecto con V-ing
can I have summed? can you have summed? can he have summed? can we have summed? can you have summed? can they have summed?	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	Forma con V-ing
can't I sum? can't you sum? can't he sum? can't we sum? can't you sum? can't they sum?	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	Perfecto con V-ing
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?	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?