English verb conjugation
COULD CROAK

Regular verb: croak - croaked - croaked

Affirmation

Simple form	V-ing form
I could croak you could croak he could croak we could croak you could croak they could croak	I could be croaking you could be croaking he could be croaking we could be croaking you could be croaking they could be croaking
Perfect	V-ing perfect
I could have croaked you could have croaked he could have croaked we could have croaked you could have croaked they could have croaked	I could have been croaking you could have been croaking he could have been croaking we could have been croaking you could have been croaking they could have been croaking

Negation

Simple form	V-ing form
I couldn't croak you couldn't croak he couldn't croak we couldn't croak you couldn't croak they couldn't croak	I couldn't be croaking you couldn't be croaking he couldn't be croaking we couldn't be croaking you couldn't be croaking they couldn't be croaking
Perfect	V-ing perfect
I couldn't have croaked you couldn't have croaked he couldn't have croaked we couldn't have croaked you couldn't have croaked they couldn't have croaked	I couldn't have been croaking you couldn't have been croaking he couldn't have been croaking we couldn't have been croaking you couldn't have been croaking they couldn't have been croaking

Interrogative form

Simple form	V-ing form
could I croak? could you croak? could he croak? could we croak? could you croak? could they croak?	could I be croaking? could you be croaking? could he be croaking? could we be croaking? could you be croaking? could they be croaking?
Perfect	V-ing perfect
could I have croaked? could you have croaked? could he have croaked? could we have croaked? could you have croaked? could they have croaked?	could I have been croaking? could you have been croaking? could he have been croaking? could we have been croaking? could you have been croaking? could they have been croaking?

Interro-negative form

Simple form	V-ing form
couldn't I croak? couldn't you croak? couldn't he croak? couldn't we croak? couldn't you croak? couldn't they croak?	couldn't I be croaking? couldn't you be croaking? couldn't he be croaking? couldn't we be croaking? couldn't you be croaking? couldn't they be croaking?
Perfect	V-ing perfect
couldn't I have croaked? couldn't you have croaked? couldn't he have croaked? couldn't we have croaked? couldn't you have croaked? couldn't they have croaked?	couldn't I have been croaking? couldn't you have been croaking? couldn't he have been croaking? couldn't we have been croaking? couldn't you have been croaking? couldn't they have been croaking?