English verb conjugation
COULD QUAKE

Regular verb: quake - quaked - quaked

Affirmation

Simple form	V-ing form
I could quake you could quake he could quake we could quake you could quake they could quake	I could be quaking you could be quaking he could be quaking we could be quaking you could be quaking they could be quaking
Perfect	V-ing perfect
I could have quaked you could have quaked he could have quaked we could have quaked you could have quaked they could have quaked	I could have been quaking you could have been quaking he could have been quaking we could have been quaking you could have been quaking they could have been quaking

Negation

Simple form	V-ing form
I couldn't quake you couldn't quake he couldn't quake we couldn't quake you couldn't quake they couldn't quake	I couldn't be quaking you couldn't be quaking he couldn't be quaking we couldn't be quaking you couldn't be quaking they couldn't be quaking
Perfect	V-ing perfect
I couldn't have quaked you couldn't have quaked he couldn't have quaked we couldn't have quaked you couldn't have quaked they couldn't have quaked	I couldn't have been quaking you couldn't have been quaking he couldn't have been quaking we couldn't have been quaking you couldn't have been quaking they couldn't have been quaking

Interrogative form

Simple form	V-ing form
could I quake? could you quake? could he quake? could we quake? could you quake? could they quake?	could I be quaking? could you be quaking? could he be quaking? could we be quaking? could you be quaking? could they be quaking?
Perfect	V-ing perfect
could I have quaked? could you have quaked? could he have quaked? could we have quaked? could you have quaked? could they have quaked?	could I have been quaking? could you have been quaking? could he have been quaking? could we have been quaking? could you have been quaking? could they have been quaking?

Interro-negative form

Simple form	V-ing form
couldn't I quake? couldn't you quake? couldn't he quake? couldn't we quake? couldn't you quake? couldn't they quake?	couldn't I be quaking? couldn't you be quaking? couldn't he be quaking? couldn't we be quaking? couldn't you be quaking? couldn't they be quaking?
Perfect	V-ing perfect
couldn't I have quaked? couldn't you have quaked? couldn't he have quaked? couldn't we have quaked? couldn't you have quaked? couldn't they have quaked?	couldn't I have been quaking? couldn't you have been quaking? couldn't he have been quaking? couldn't we have been quaking? couldn't you have been quaking? couldn't they have been quaking?