English verb conjugation
COULD TRIP

Regular verb: trip - tripped - tripped

Affirmation

Simple form	V-ing form
I could trip you could trip he could trip we could trip you could trip they could trip	I could be tripping you could be tripping he could be tripping we could be tripping you could be tripping they could be tripping
Perfect	V-ing perfect
I could have tripped you could have tripped he could have tripped we could have tripped you could have tripped they could have tripped	I could have been tripping you could have been tripping he could have been tripping we could have been tripping you could have been tripping they could have been tripping

Negation

Simple form	V-ing form
I couldn't trip you couldn't trip he couldn't trip we couldn't trip you couldn't trip they couldn't trip	I couldn't be tripping you couldn't be tripping he couldn't be tripping we couldn't be tripping you couldn't be tripping they couldn't be tripping
Perfect	V-ing perfect
I couldn't have tripped you couldn't have tripped he couldn't have tripped we couldn't have tripped you couldn't have tripped they couldn't have tripped	I couldn't have been tripping you couldn't have been tripping he couldn't have been tripping we couldn't have been tripping you couldn't have been tripping they couldn't have been tripping

Interrogative form

Simple form	V-ing form
could I trip? could you trip? could he trip? could we trip? could you trip? could they trip?	could I be tripping? could you be tripping? could he be tripping? could we be tripping? could you be tripping? could they be tripping?
Perfect	V-ing perfect
could I have tripped? could you have tripped? could he have tripped? could we have tripped? could you have tripped? could they have tripped?	could I have been tripping? could you have been tripping? could he have been tripping? could we have been tripping? could you have been tripping? could they have been tripping?

Interro-negative form

Simple form	V-ing form
couldn't I trip? couldn't you trip? couldn't he trip? couldn't we trip? couldn't you trip? couldn't they trip?	couldn't I be tripping? couldn't you be tripping? couldn't he be tripping? couldn't we be tripping? couldn't you be tripping? couldn't they be tripping?
Perfect	V-ing perfect
couldn't I have tripped? couldn't you have tripped? couldn't he have tripped? couldn't we have tripped? couldn't you have tripped? couldn't they have tripped?	couldn't I have been tripping? couldn't you have been tripping? couldn't he have been tripping? couldn't we have been tripping? couldn't you have been tripping? couldn't they have been tripping?