I can sightsee you can sightsee he can sightsee we can sightsee you can sightsee they can sightsee
Forma com V-ing
I can be sightseeing you can be sightseeing he can be sightseeing we can be sightseeing you can be sightseeing they can be sightseeing
Perfeito
I can have sightseed you can have sightseed he can have sightseed we can have sightseed you can have sightseed they can have sightseed
Perfeito com V-ing
I can have been sightseeing you can have been sightseeing he can have been sightseeing we can have been sightseeing you can have been sightseeing they can have been sightseeing
Negação
Forma simple
I can't sightsee you can't sightsee he can't sightsee we can't sightsee you can't sightsee they can't sightsee
Forma com V-ing
I can't be sightseeing you can't be sightseeing he can't be sightseeing we can't be sightseeing you can't be sightseeing they can't be sightseeing
Perfeito
I can't have sightseed you can't have sightseed he can't have sightseed we can't have sightseed you can't have sightseed they can't have sightseed
Perfeito com V-ing
I can't have been sightseeing you can't have been sightseeing he can't have been sightseeing we can't have been sightseeing you can't have been sightseeing they can't have been sightseeing
Forma interrogativa
Forma simple
can I sightsee? can you sightsee? can he sightsee? can we sightsee? can you sightsee? can they sightsee?
Forma com V-ing
can I be sightseeing? can you be sightseeing? can he be sightseeing? can we be sightseeing? can you be sightseeing? can they be sightseeing?
Perfeito
can I have sightseed? can you have sightseed? can he have sightseed? can we have sightseed? can you have sightseed? can they have sightseed?
Perfeito com V-ing
can I have been sightseeing? can you have been sightseeing? can he have been sightseeing? can we have been sightseeing? can you have been sightseeing? can they have been sightseeing?
Forma interro-Negação
Forma simple
can't I sightsee? can't you sightsee? can't he sightsee? can't we sightsee? can't you sightsee? can't they sightsee?
Forma com V-ing
can't I be sightseeing? can't you be sightseeing? can't he be sightseeing? can't we be sightseeing? can't you be sightseeing? can't they be sightseeing?
Perfeito
can't I have sightseed? can't you have sightseed? can't he have sightseed? can't we have sightseed? can't you have sightseed? can't they have sightseed?
Perfeito com V-ing
can't I have been sightseeing? can't you have been sightseeing? can't he have been sightseeing? can't we have been sightseeing? can't you have been sightseeing? can't they have been sightseeing?