I could follow you could follow he could follow we could follow you could follow they could follow
Forma com V-ing
I could be following you could be following he could be following we could be following you could be following they could be following
Perfeito
I could have followed you could have followed he could have followed we could have followed you could have followed they could have followed
Perfeito com V-ing
I could have been following you could have been following he could have been following we could have been following you could have been following they could have been following
Negação
Forma simple
I could not follow you could not follow he could not follow we could not follow you could not follow they could not follow
Forma com V-ing
I could not be following you could not be following he could not be following we could not be following you could not be following they could not be following
Perfeito
I could not have followed you could not have followed he could not have followed we could not have followed you could not have followed they could not have followed
Perfeito com V-ing
I could not have been following you could not have been following he could not have been following we could not have been following you could not have been following they could not have been following
Forma interrogativa
Forma simple
could I follow? could you follow? could he follow? could we follow? could you follow? could they follow?
Forma com V-ing
could I be following? could you be following? could he be following? could we be following? could you be following? could they be following?
Perfeito
could I have followed? could you have followed? could he have followed? could we have followed? could you have followed? could they have followed?
Perfeito com V-ing
could I have been following? could you have been following? could he have been following? could we have been following? could you have been following? could they have been following?
Forma interro-Negação
Forma simple
could I not follow? could you not follow? could he not follow? could we not follow? could you not follow? could they not follow?
Forma com V-ing
could I not be following? could you not be following? could he not be following? could we not be following? could you not be following? could they not be following?
Perfeito
could I not have followed? could you not have followed? could he not have followed? could we not have followed? could you not have followed? could they not have followed?
Perfeito com V-ing
could I not have been following? could you not have been following? could he not have been following? could we not have been following? could you not have been following? could they not have been following?