English verb conjugation
COULD HEADBUTT

Regular verb: headbutt - headbutted - headbutted

Affirmation

Simple form	V-ing form
I could headbutt you could headbutt she could headbutt we could headbutt you could headbutt they could headbutt	I could be headbutting you could be headbutting she could be headbutting we could be headbutting you could be headbutting they could be headbutting
Perfect	V-ing perfect
I could have headbutted you could have headbutted she could have headbutted we could have headbutted you could have headbutted they could have headbutted	I could have been headbutting you could have been headbutting she could have been headbutting we could have been headbutting you could have been headbutting they could have been headbutting

Negation

Simple form	V-ing form
I couldn't headbutt you couldn't headbutt she couldn't headbutt we couldn't headbutt you couldn't headbutt they couldn't headbutt	I couldn't be headbutting you couldn't be headbutting she couldn't be headbutting we couldn't be headbutting you couldn't be headbutting they couldn't be headbutting
Perfect	V-ing perfect
I couldn't have headbutted you couldn't have headbutted she couldn't have headbutted we couldn't have headbutted you couldn't have headbutted they couldn't have headbutted	I couldn't have been headbutting you couldn't have been headbutting she couldn't have been headbutting we couldn't have been headbutting you couldn't have been headbutting they couldn't have been headbutting

Interrogative form

Simple form	V-ing form
could I headbutt? could you headbutt? could she headbutt? could we headbutt? could you headbutt? could they headbutt?	could I be headbutting? could you be headbutting? could she be headbutting? could we be headbutting? could you be headbutting? could they be headbutting?
Perfect	V-ing perfect
could I have headbutted? could you have headbutted? could she have headbutted? could we have headbutted? could you have headbutted? could they have headbutted?	could I have been headbutting? could you have been headbutting? could she have been headbutting? could we have been headbutting? could you have been headbutting? could they have been headbutting?

Interro-negative form

Simple form	V-ing form
couldn't I headbutt? couldn't you headbutt? couldn't she headbutt? couldn't we headbutt? couldn't you headbutt? couldn't they headbutt?	couldn't I be headbutting? couldn't you be headbutting? couldn't she be headbutting? couldn't we be headbutting? couldn't you be headbutting? couldn't they be headbutting?
Perfect	V-ing perfect
couldn't I have headbutted? couldn't you have headbutted? couldn't she have headbutted? couldn't we have headbutted? couldn't you have headbutted? couldn't they have headbutted?	couldn't I have been headbutting? couldn't you have been headbutting? couldn't she have been headbutting? couldn't we have been headbutting? couldn't you have been headbutting? couldn't they have been headbutting?