I can warn you can warn he can warn we can warn you can warn they can warn
Forma com V-ing
I can be warning you can be warning he can be warning we can be warning you can be warning they can be warning
Perfeito
I can have warned you can have warned he can have warned we can have warned you can have warned they can have warned
Perfeito com V-ing
I can have been warning you can have been warning he can have been warning we can have been warning you can have been warning they can have been warning
Negação
Forma simple
I cannot warn you cannot warn he cannot warn we cannot warn you cannot warn they cannot warn
Forma com V-ing
I cannot be warning you cannot be warning he cannot be warning we cannot be warning you cannot be warning they cannot be warning
Perfeito
I cannot have warned you cannot have warned he cannot have warned we cannot have warned you cannot have warned they cannot have warned
Perfeito com V-ing
I cannot have been warning you cannot have been warning he cannot have been warning we cannot have been warning you cannot have been warning they cannot have been warning
Forma interrogativa
Forma simple
can I warn? can you warn? can he warn? can we warn? can you warn? can they warn?
Forma com V-ing
can I be warning? can you be warning? can he be warning? can we be warning? can you be warning? can they be warning?
Perfeito
can I have warned? can you have warned? can he have warned? can we have warned? can you have warned? can they have warned?
Perfeito com V-ing
can I have been warning? can you have been warning? can he have been warning? can we have been warning? can you have been warning? can they have been warning?
Forma interro-Negação
Forma simple
can I not warn? can you not warn? can he not warn? can we not warn? can you not warn? can they not warn?
Forma com V-ing
can I not be warning? can you not be warning? can he not be warning? can we not be warning? can you not be warning? can they not be warning?
Perfeito
can I not have warned? can you not have warned? can he not have warned? can we not have warned? can you not have warned? can they not have warned?
Perfeito com V-ing
can I not have been warning? can you not have been warning? can he not have been warning? can we not have been warning? can you not have been warning? can they not have been warning?