English verb conjugation
COULD LAND

Regular verb: land - landed - landed

Affirmation

Simple form	V-ing form
I could land you could land he could land we could land you could land they could land	I could be landing you could be landing he could be landing we could be landing you could be landing they could be landing
Perfect	V-ing perfect
I could have landed you could have landed he could have landed we could have landed you could have landed they could have landed	I could have been landing you could have been landing he could have been landing we could have been landing you could have been landing they could have been landing

Negation

Simple form	V-ing form
I could not land you could not land he could not land we could not land you could not land they could not land	I could not be landing you could not be landing he could not be landing we could not be landing you could not be landing they could not be landing
Perfect	V-ing perfect
I could not have landed you could not have landed he could not have landed we could not have landed you could not have landed they could not have landed	I could not have been landing you could not have been landing he could not have been landing we could not have been landing you could not have been landing they could not have been landing

Interrogative form

Simple form	V-ing form
could I land? could you land? could he land? could we land? could you land? could they land?	could I be landing? could you be landing? could he be landing? could we be landing? could you be landing? could they be landing?
Perfect	V-ing perfect
could I have landed? could you have landed? could he have landed? could we have landed? could you have landed? could they have landed?	could I have been landing? could you have been landing? could he have been landing? could we have been landing? could you have been landing? could they have been landing?

Interro-negative form

Simple form	V-ing form
could I not land? could you not land? could he not land? could we not land? could you not land? could they not land?	could I not be landing? could you not be landing? could he not be landing? could we not be landing? could you not be landing? could they not be landing?
Perfect	V-ing perfect
could I not have landed? could you not have landed? could he not have landed? could we not have landed? could you not have landed? could they not have landed?	could I not have been landing? could you not have been landing? could he not have been landing? could we not have been landing? could you not have been landing? could they not have been landing?