I could untwist you could untwist she could untwist we could untwist you could untwist they could untwist
V-ing form
I could be untwisting you could be untwisting she could be untwisting we could be untwisting you could be untwisting they could be untwisting
Perfect
I could have untwisted you could have untwisted she could have untwisted we could have untwisted you could have untwisted they could have untwisted
V-ing perfect
I could have been untwisting you could have been untwisting she could have been untwisting we could have been untwisting you could have been untwisting they could have been untwisting
Negation
Simple form
I couldn't untwist you couldn't untwist she couldn't untwist we couldn't untwist you couldn't untwist they couldn't untwist
V-ing form
I couldn't be untwisting you couldn't be untwisting she couldn't be untwisting we couldn't be untwisting you couldn't be untwisting they couldn't be untwisting
Perfect
I couldn't have untwisted you couldn't have untwisted she couldn't have untwisted we couldn't have untwisted you couldn't have untwisted they couldn't have untwisted
V-ing perfect
I couldn't have been untwisting you couldn't have been untwisting she couldn't have been untwisting we couldn't have been untwisting you couldn't have been untwisting they couldn't have been untwisting
Interrogative form
Simple form
could I untwist? could you untwist? could she untwist? could we untwist? could you untwist? could they untwist?
V-ing form
could I be untwisting? could you be untwisting? could she be untwisting? could we be untwisting? could you be untwisting? could they be untwisting?
Perfect
could I have untwisted? could you have untwisted? could she have untwisted? could we have untwisted? could you have untwisted? could they have untwisted?
V-ing perfect
could I have been untwisting? could you have been untwisting? could she have been untwisting? could we have been untwisting? could you have been untwisting? could they have been untwisting?
Interro-negative form
Simple form
couldn't I untwist? couldn't you untwist? couldn't she untwist? couldn't we untwist? couldn't you untwist? couldn't they untwist?
V-ing form
couldn't I be untwisting? couldn't you be untwisting? couldn't she be untwisting? couldn't we be untwisting? couldn't you be untwisting? couldn't they be untwisting?
Perfect
couldn't I have untwisted? couldn't you have untwisted? couldn't she have untwisted? couldn't we have untwisted? couldn't you have untwisted? couldn't they have untwisted?
V-ing perfect
couldn't I have been untwisting? couldn't you have been untwisting? couldn't she have been untwisting? couldn't we have been untwisting? couldn't you have been untwisting? couldn't they have been untwisting?