English verb conjugation
COULD STILL

Regular verb: still - stilled - stilled

Affirmation

Simple form	V-ing form
I could still you could still he could still we could still you could still they could still	I could be stilling you could be stilling he could be stilling we could be stilling you could be stilling they could be stilling
Perfect	V-ing perfect
I could have stilled you could have stilled he could have stilled we could have stilled you could have stilled they could have stilled	I could have been stilling you could have been stilling he could have been stilling we could have been stilling you could have been stilling they could have been stilling

Negation

Simple form	V-ing form
I couldn't still you couldn't still he couldn't still we couldn't still you couldn't still they couldn't still	I couldn't be stilling you couldn't be stilling he couldn't be stilling we couldn't be stilling you couldn't be stilling they couldn't be stilling
Perfect	V-ing perfect
I couldn't have stilled you couldn't have stilled he couldn't have stilled we couldn't have stilled you couldn't have stilled they couldn't have stilled	I couldn't have been stilling you couldn't have been stilling he couldn't have been stilling we couldn't have been stilling you couldn't have been stilling they couldn't have been stilling

Interrogative form

Simple form	V-ing form
could I still? could you still? could he still? could we still? could you still? could they still?	could I be stilling? could you be stilling? could he be stilling? could we be stilling? could you be stilling? could they be stilling?
Perfect	V-ing perfect
could I have stilled? could you have stilled? could he have stilled? could we have stilled? could you have stilled? could they have stilled?	could I have been stilling? could you have been stilling? could he have been stilling? could we have been stilling? could you have been stilling? could they have been stilling?

Interro-negative form

Simple form	V-ing form
couldn't I still? couldn't you still? couldn't he still? couldn't we still? couldn't you still? couldn't they still?	couldn't I be stilling? couldn't you be stilling? couldn't he be stilling? couldn't we be stilling? couldn't you be stilling? couldn't they be stilling?
Perfect	V-ing perfect
couldn't I have stilled? couldn't you have stilled? couldn't he have stilled? couldn't we have stilled? couldn't you have stilled? couldn't they have stilled?	couldn't I have been stilling? couldn't you have been stilling? couldn't he have been stilling? couldn't we have been stilling? couldn't you have been stilling? couldn't they have been stilling?