English verb conjugation
COULD UNTIE

Regular verb: untie - untied - untied

Affirmation

Simple form	V-ing form
I could untie you could untie he could untie we could untie you could untie they could untie	I could be untying you could be untying he could be untying we could be untying you could be untying they could be untying
Perfect	V-ing perfect
I could have untied you could have untied he could have untied we could have untied you could have untied they could have untied	I could have been untying you could have been untying he could have been untying we could have been untying you could have been untying they could have been untying

Negation

Simple form	V-ing form
I couldn't untie you couldn't untie he couldn't untie we couldn't untie you couldn't untie they couldn't untie	I couldn't be untying you couldn't be untying he couldn't be untying we couldn't be untying you couldn't be untying they couldn't be untying
Perfect	V-ing perfect
I couldn't have untied you couldn't have untied he couldn't have untied we couldn't have untied you couldn't have untied they couldn't have untied	I couldn't have been untying you couldn't have been untying he couldn't have been untying we couldn't have been untying you couldn't have been untying they couldn't have been untying

Interrogative form

Simple form	V-ing form
could I untie? could you untie? could he untie? could we untie? could you untie? could they untie?	could I be untying? could you be untying? could he be untying? could we be untying? could you be untying? could they be untying?
Perfect	V-ing perfect
could I have untied? could you have untied? could he have untied? could we have untied? could you have untied? could they have untied?	could I have been untying? could you have been untying? could he have been untying? could we have been untying? could you have been untying? could they have been untying?

Interro-negative form

Simple form	V-ing form
couldn't I untie? couldn't you untie? couldn't he untie? couldn't we untie? couldn't you untie? couldn't they untie?	couldn't I be untying? couldn't you be untying? couldn't he be untying? couldn't we be untying? couldn't you be untying? couldn't they be untying?
Perfect	V-ing perfect
couldn't I have untied? couldn't you have untied? couldn't he have untied? couldn't we have untied? couldn't you have untied? couldn't they have untied?	couldn't I have been untying? couldn't you have been untying? couldn't he have been untying? couldn't we have been untying? couldn't you have been untying? couldn't they have been untying?