I can warn you can warn she can warn we can warn you can warn they can warn
Forma com V-ing
I can be warning you can be warning she can be warning we can be warning you can be warning they can be warning
Perfeito
I can have warned you can have warned she 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 she can have been warning we can have been warning you can have been warning they can have been warning
Negação
Forma simple
I can't warn you can't warn she can't warn we can't warn you can't warn they can't warn
Forma com V-ing
I can't be warning you can't be warning she can't be warning we can't be warning you can't be warning they can't be warning
Perfeito
I can't have warned you can't have warned she can't have warned we can't have warned you can't have warned they can't have warned
Perfeito com V-ing
I can't have been warning you can't have been warning she can't have been warning we can't have been warning you can't have been warning they can't have been warning
Forma interrogativa
Forma simple
can I warn? can you warn? can she warn? can we warn? can you warn? can they warn?
Forma com V-ing
can I be warning? can you be warning? can she be warning? can we be warning? can you be warning? can they be warning?
Perfeito
can I have warned? can you have warned? can she 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 she have been warning? can we have been warning? can you have been warning? can they have been warning?
Forma interro-Negação
Forma simple
can't I warn? can't you warn? can't she warn? can't we warn? can't you warn? can't they warn?
Forma com V-ing
can't I be warning? can't you be warning? can't she be warning? can't we be warning? can't you be warning? can't they be warning?
Perfeito
can't I have warned? can't you have warned? can't she have warned? can't we have warned? can't you have warned? can't they have warned?
Perfeito com V-ing
can't I have been warning? can't you have been warning? can't she have been warning? can't we have been warning? can't you have been warning? can't they have been warning?