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 couldn't land you couldn't land he couldn't land we couldn't land you couldn't land they couldn't land	I couldn't be landing you couldn't be landing he couldn't be landing we couldn't be landing you couldn't be landing they couldn't be landing
Perfect	V-ing perfect
I couldn't have landed you couldn't have landed he couldn't have landed we couldn't have landed you couldn't have landed they couldn't have landed	I couldn't have been landing you couldn't have been landing he couldn't have been landing we couldn't have been landing you couldn't have been landing they couldn't 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
couldn't I land? couldn't you land? couldn't he land? couldn't we land? couldn't you land? couldn't they land?	couldn't I be landing? couldn't you be landing? couldn't he be landing? couldn't we be landing? couldn't you be landing? couldn't they be landing?
Perfect	V-ing perfect
couldn't I have landed? couldn't you have landed? couldn't he have landed? couldn't we have landed? couldn't you have landed? couldn't they have landed?	couldn't I have been landing? couldn't you have been landing? couldn't he have been landing? couldn't we have been landing? couldn't you have been landing? couldn't they have been landing?