English verb conjugation
COULD TOPPLE

Regular verb: topple - toppled - toppled

Affirmation

Simple form	V-ing form
I could topple you could topple she could topple we could topple you could topple they could topple	I could be toppling you could be toppling she could be toppling we could be toppling you could be toppling they could be toppling
Perfect	V-ing perfect
I could have toppled you could have toppled she could have toppled we could have toppled you could have toppled they could have toppled	I could have been toppling you could have been toppling she could have been toppling we could have been toppling you could have been toppling they could have been toppling

Negation

Simple form	V-ing form
I couldn't topple you couldn't topple she couldn't topple we couldn't topple you couldn't topple they couldn't topple	I couldn't be toppling you couldn't be toppling she couldn't be toppling we couldn't be toppling you couldn't be toppling they couldn't be toppling
Perfect	V-ing perfect
I couldn't have toppled you couldn't have toppled she couldn't have toppled we couldn't have toppled you couldn't have toppled they couldn't have toppled	I couldn't have been toppling you couldn't have been toppling she couldn't have been toppling we couldn't have been toppling you couldn't have been toppling they couldn't have been toppling

Interrogative form

Simple form	V-ing form
could I topple? could you topple? could she topple? could we topple? could you topple? could they topple?	could I be toppling? could you be toppling? could she be toppling? could we be toppling? could you be toppling? could they be toppling?
Perfect	V-ing perfect
could I have toppled? could you have toppled? could she have toppled? could we have toppled? could you have toppled? could they have toppled?	could I have been toppling? could you have been toppling? could she have been toppling? could we have been toppling? could you have been toppling? could they have been toppling?

Interro-negative form

Simple form	V-ing form
couldn't I topple? couldn't you topple? couldn't she topple? couldn't we topple? couldn't you topple? couldn't they topple?	couldn't I be toppling? couldn't you be toppling? couldn't she be toppling? couldn't we be toppling? couldn't you be toppling? couldn't they be toppling?
Perfect	V-ing perfect
couldn't I have toppled? couldn't you have toppled? couldn't she have toppled? couldn't we have toppled? couldn't you have toppled? couldn't they have toppled?	couldn't I have been toppling? couldn't you have been toppling? couldn't she have been toppling? couldn't we have been toppling? couldn't you have been toppling? couldn't they have been toppling?