I can witness you can witness he can witness we can witness you can witness they can witness
Forma com V-ing
I can be witnessing you can be witnessing he can be witnessing we can be witnessing you can be witnessing they can be witnessing
Perfeito
I can have witnessed you can have witnessed he can have witnessed we can have witnessed you can have witnessed they can have witnessed
Perfeito com V-ing
I can have been witnessing you can have been witnessing he can have been witnessing we can have been witnessing you can have been witnessing they can have been witnessing
Negação
Forma simple
I can't witness you can't witness he can't witness we can't witness you can't witness they can't witness
Forma com V-ing
I can't be witnessing you can't be witnessing he can't be witnessing we can't be witnessing you can't be witnessing they can't be witnessing
Perfeito
I can't have witnessed you can't have witnessed he can't have witnessed we can't have witnessed you can't have witnessed they can't have witnessed
Perfeito com V-ing
I can't have been witnessing you can't have been witnessing he can't have been witnessing we can't have been witnessing you can't have been witnessing they can't have been witnessing
Forma interrogativa
Forma simple
can I witness? can you witness? can he witness? can we witness? can you witness? can they witness?
Forma com V-ing
can I be witnessing? can you be witnessing? can he be witnessing? can we be witnessing? can you be witnessing? can they be witnessing?
Perfeito
can I have witnessed? can you have witnessed? can he have witnessed? can we have witnessed? can you have witnessed? can they have witnessed?
Perfeito com V-ing
can I have been witnessing? can you have been witnessing? can he have been witnessing? can we have been witnessing? can you have been witnessing? can they have been witnessing?
Forma interro-Negação
Forma simple
can't I witness? can't you witness? can't he witness? can't we witness? can't you witness? can't they witness?
Forma com V-ing
can't I be witnessing? can't you be witnessing? can't he be witnessing? can't we be witnessing? can't you be witnessing? can't they be witnessing?
Perfeito
can't I have witnessed? can't you have witnessed? can't he have witnessed? can't we have witnessed? can't you have witnessed? can't they have witnessed?
Perfeito com V-ing
can't I have been witnessing? can't you have been witnessing? can't he have been witnessing? can't we have been witnessing? can't you have been witnessing? can't they have been witnessing?