I can stumble you can stumble he can stumble we can stumble you can stumble they can stumble
Forma com V-ing
I can be stumbling you can be stumbling he can be stumbling we can be stumbling you can be stumbling they can be stumbling
Perfeito
I can have stumbled you can have stumbled he can have stumbled we can have stumbled you can have stumbled they can have stumbled
Perfeito com V-ing
I can have been stumbling you can have been stumbling he can have been stumbling we can have been stumbling you can have been stumbling they can have been stumbling
Negação
Forma simple
I cannot stumble you cannot stumble he cannot stumble we cannot stumble you cannot stumble they cannot stumble
Forma com V-ing
I cannot be stumbling you cannot be stumbling he cannot be stumbling we cannot be stumbling you cannot be stumbling they cannot be stumbling
Perfeito
I cannot have stumbled you cannot have stumbled he cannot have stumbled we cannot have stumbled you cannot have stumbled they cannot have stumbled
Perfeito com V-ing
I cannot have been stumbling you cannot have been stumbling he cannot have been stumbling we cannot have been stumbling you cannot have been stumbling they cannot have been stumbling
Forma interrogativa
Forma simple
can I stumble? can you stumble? can he stumble? can we stumble? can you stumble? can they stumble?
Forma com V-ing
can I be stumbling? can you be stumbling? can he be stumbling? can we be stumbling? can you be stumbling? can they be stumbling?
Perfeito
can I have stumbled? can you have stumbled? can he have stumbled? can we have stumbled? can you have stumbled? can they have stumbled?
Perfeito com V-ing
can I have been stumbling? can you have been stumbling? can he have been stumbling? can we have been stumbling? can you have been stumbling? can they have been stumbling?
Forma interro-Negação
Forma simple
can I not stumble? can you not stumble? can he not stumble? can we not stumble? can you not stumble? can they not stumble?
Forma com V-ing
can I not be stumbling? can you not be stumbling? can he not be stumbling? can we not be stumbling? can you not be stumbling? can they not be stumbling?
Perfeito
can I not have stumbled? can you not have stumbled? can he not have stumbled? can we not have stumbled? can you not have stumbled? can they not have stumbled?
Perfeito com V-ing
can I not have been stumbling? can you not have been stumbling? can he not have been stumbling? can we not have been stumbling? can you not have been stumbling? can they not have been stumbling?