English verb conjugation
COULD BOARD

Regular verb: board - boarded - boarded

Affirmation

Simple form	V-ing form
I could board you could board he could board we could board you could board they could board	I could be boarding you could be boarding he could be boarding we could be boarding you could be boarding they could be boarding
Perfect	V-ing perfect
I could have boarded you could have boarded he could have boarded we could have boarded you could have boarded they could have boarded	I could have been boarding you could have been boarding he could have been boarding we could have been boarding you could have been boarding they could have been boarding

Negation

Simple form	V-ing form
I couldn't board you couldn't board he couldn't board we couldn't board you couldn't board they couldn't board	I couldn't be boarding you couldn't be boarding he couldn't be boarding we couldn't be boarding you couldn't be boarding they couldn't be boarding
Perfect	V-ing perfect
I couldn't have boarded you couldn't have boarded he couldn't have boarded we couldn't have boarded you couldn't have boarded they couldn't have boarded	I couldn't have been boarding you couldn't have been boarding he couldn't have been boarding we couldn't have been boarding you couldn't have been boarding they couldn't have been boarding

Interrogative form

Simple form	V-ing form
could I board? could you board? could he board? could we board? could you board? could they board?	could I be boarding? could you be boarding? could he be boarding? could we be boarding? could you be boarding? could they be boarding?
Perfect	V-ing perfect
could I have boarded? could you have boarded? could he have boarded? could we have boarded? could you have boarded? could they have boarded?	could I have been boarding? could you have been boarding? could he have been boarding? could we have been boarding? could you have been boarding? could they have been boarding?

Interro-negative form

Simple form	V-ing form
couldn't I board? couldn't you board? couldn't he board? couldn't we board? couldn't you board? couldn't they board?	couldn't I be boarding? couldn't you be boarding? couldn't he be boarding? couldn't we be boarding? couldn't you be boarding? couldn't they be boarding?
Perfect	V-ing perfect
couldn't I have boarded? couldn't you have boarded? couldn't he have boarded? couldn't we have boarded? couldn't you have boarded? couldn't they have boarded?	couldn't I have been boarding? couldn't you have been boarding? couldn't he have been boarding? couldn't we have been boarding? couldn't you have been boarding? couldn't they have been boarding?