I can occur you can occur he can occur we can occur you can occur they can occur
Forma com V-ing
I can be occurring you can be occurring he can be occurring we can be occurring you can be occurring they can be occurring
Perfeito
I can have occurred you can have occurred he can have occurred we can have occurred you can have occurred they can have occurred
Perfeito com V-ing
I can have been occurring you can have been occurring he can have been occurring we can have been occurring you can have been occurring they can have been occurring
Negação
Forma simple
I cannot occur you cannot occur he cannot occur we cannot occur you cannot occur they cannot occur
Forma com V-ing
I cannot be occurring you cannot be occurring he cannot be occurring we cannot be occurring you cannot be occurring they cannot be occurring
Perfeito
I cannot have occurred you cannot have occurred he cannot have occurred we cannot have occurred you cannot have occurred they cannot have occurred
Perfeito com V-ing
I cannot have been occurring you cannot have been occurring he cannot have been occurring we cannot have been occurring you cannot have been occurring they cannot have been occurring
Forma interrogativa
Forma simple
can I occur? can you occur? can he occur? can we occur? can you occur? can they occur?
Forma com V-ing
can I be occurring? can you be occurring? can he be occurring? can we be occurring? can you be occurring? can they be occurring?
Perfeito
can I have occurred? can you have occurred? can he have occurred? can we have occurred? can you have occurred? can they have occurred?
Perfeito com V-ing
can I have been occurring? can you have been occurring? can he have been occurring? can we have been occurring? can you have been occurring? can they have been occurring?
Forma interro-Negação
Forma simple
can I not occur? can you not occur? can he not occur? can we not occur? can you not occur? can they not occur?
Forma com V-ing
can I not be occurring? can you not be occurring? can he not be occurring? can we not be occurring? can you not be occurring? can they not be occurring?
Perfeito
can I not have occurred? can you not have occurred? can he not have occurred? can we not have occurred? can you not have occurred? can they not have occurred?
Perfeito com V-ing
can I not have been occurring? can you not have been occurring? can he not have been occurring? can we not have been occurring? can you not have been occurring? can they not have been occurring?