English verb conjugation
COULD SIGHTSEE

Regular verb: sightsee - sightseed - sightseed

Affirmation

Simple form	V-ing form
I could sightsee you could sightsee he could sightsee we could sightsee you could sightsee they could sightsee	I could be sightseeing you could be sightseeing he could be sightseeing we could be sightseeing you could be sightseeing they could be sightseeing
Perfect	V-ing perfect
I could have sightseed you could have sightseed he could have sightseed we could have sightseed you could have sightseed they could have sightseed	I could have been sightseeing you could have been sightseeing he could have been sightseeing we could have been sightseeing you could have been sightseeing they could have been sightseeing

Negation

Simple form	V-ing form
I couldn't sightsee you couldn't sightsee he couldn't sightsee we couldn't sightsee you couldn't sightsee they couldn't sightsee	I couldn't be sightseeing you couldn't be sightseeing he couldn't be sightseeing we couldn't be sightseeing you couldn't be sightseeing they couldn't be sightseeing
Perfect	V-ing perfect
I couldn't have sightseed you couldn't have sightseed he couldn't have sightseed we couldn't have sightseed you couldn't have sightseed they couldn't have sightseed	I couldn't have been sightseeing you couldn't have been sightseeing he couldn't have been sightseeing we couldn't have been sightseeing you couldn't have been sightseeing they couldn't have been sightseeing

Interrogative form

Simple form	V-ing form
could I sightsee? could you sightsee? could he sightsee? could we sightsee? could you sightsee? could they sightsee?	could I be sightseeing? could you be sightseeing? could he be sightseeing? could we be sightseeing? could you be sightseeing? could they be sightseeing?
Perfect	V-ing perfect
could I have sightseed? could you have sightseed? could he have sightseed? could we have sightseed? could you have sightseed? could they have sightseed?	could I have been sightseeing? could you have been sightseeing? could he have been sightseeing? could we have been sightseeing? could you have been sightseeing? could they have been sightseeing?

Interro-negative form

Simple form	V-ing form
couldn't I sightsee? couldn't you sightsee? couldn't he sightsee? couldn't we sightsee? couldn't you sightsee? couldn't they sightsee?	couldn't I be sightseeing? couldn't you be sightseeing? couldn't he be sightseeing? couldn't we be sightseeing? couldn't you be sightseeing? couldn't they be sightseeing?
Perfect	V-ing perfect
couldn't I have sightseed? couldn't you have sightseed? couldn't he have sightseed? couldn't we have sightseed? couldn't you have sightseed? couldn't they have sightseed?	couldn't I have been sightseeing? couldn't you have been sightseeing? couldn't he have been sightseeing? couldn't we have been sightseeing? couldn't you have been sightseeing? couldn't they have been sightseeing?