English verb conjugation
CAN CROAK

Regular verb: croak - croaked - croaked

Affirmation

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

Negation

Simple form	V-ing form
I cannot croak you cannot croak she cannot croak we cannot croak you cannot croak they cannot croak	I cannot be croaking you cannot be croaking she cannot be croaking we cannot be croaking you cannot be croaking they cannot be croaking
Perfect	V-ing perfect
I cannot have croaked you cannot have croaked she cannot have croaked we cannot have croaked you cannot have croaked they cannot have croaked	I cannot have been croaking you cannot have been croaking she cannot have been croaking we cannot have been croaking you cannot have been croaking they cannot have been croaking

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can I not croak? can you not croak? can she not croak? can we not croak? can you not croak? can they not croak?	can I not be croaking? can you not be croaking? can she not be croaking? can we not be croaking? can you not be croaking? can they not be croaking?
Perfect	V-ing perfect
can I not have croaked? can you not have croaked? can she not have croaked? can we not have croaked? can you not have croaked? can they not have croaked?	can I not have been croaking? can you not have been croaking? can she not have been croaking? can we not have been croaking? can you not have been croaking? can they not have been croaking?