English verb conjugation
COULD BURN

Regular verb: burn - burned - burned

Affirmation

Simple form	V-ing form
I could burn you could burn she could burn we could burn you could burn they could burn	I could be burning you could be burning she could be burning we could be burning you could be burning they could be burning
Perfect	V-ing perfect
I could have burned you could have burned she could have burned we could have burned you could have burned they could have burned	I could have been burning you could have been burning she could have been burning we could have been burning you could have been burning they could have been burning

Negation

Simple form	V-ing form
I couldn't burn you couldn't burn she couldn't burn we couldn't burn you couldn't burn they couldn't burn	I couldn't be burning you couldn't be burning she couldn't be burning we couldn't be burning you couldn't be burning they couldn't be burning
Perfect	V-ing perfect
I couldn't have burned you couldn't have burned she couldn't have burned we couldn't have burned you couldn't have burned they couldn't have burned	I couldn't have been burning you couldn't have been burning she couldn't have been burning we couldn't have been burning you couldn't have been burning they couldn't have been burning

Interrogative form

Simple form	V-ing form
could I burn? could you burn? could she burn? could we burn? could you burn? could they burn?	could I be burning? could you be burning? could she be burning? could we be burning? could you be burning? could they be burning?
Perfect	V-ing perfect
could I have burned? could you have burned? could she have burned? could we have burned? could you have burned? could they have burned?	could I have been burning? could you have been burning? could she have been burning? could we have been burning? could you have been burning? could they have been burning?

Interro-negative form

Simple form	V-ing form
couldn't I burn? couldn't you burn? couldn't she burn? couldn't we burn? couldn't you burn? couldn't they burn?	couldn't I be burning? couldn't you be burning? couldn't she be burning? couldn't we be burning? couldn't you be burning? couldn't they be burning?
Perfect	V-ing perfect
couldn't I have burned? couldn't you have burned? couldn't she have burned? couldn't we have burned? couldn't you have burned? couldn't they have burned?	couldn't I have been burning? couldn't you have been burning? couldn't she have been burning? couldn't we have been burning? couldn't you have been burning? couldn't they have been burning?