English verb conjugation
CAN STUMBLE

Regular verb: stumble - stumbled - stumbled

Affirmation

Simple form	V-ing form
I can stumble you can stumble he can stumble we can stumble you can stumble they can stumble	I can be stumbling you can be stumbling he can be stumbling we can be stumbling you can be stumbling they can be stumbling
Perfect	V-ing perfect
I can have stumbled you can have stumbled he can have stumbled we can have stumbled you can have stumbled they can have stumbled	I can have been stumbling you can have been stumbling he can have been stumbling we can have been stumbling you can have been stumbling they can have been stumbling

Negation

Simple form	V-ing form
I can't stumble you can't stumble he can't stumble we can't stumble you can't stumble they can't stumble	I can't be stumbling you can't be stumbling he can't be stumbling we can't be stumbling you can't be stumbling they can't be stumbling
Perfect	V-ing perfect
I can't have stumbled you can't have stumbled he can't have stumbled we can't have stumbled you can't have stumbled they can't have stumbled	I can't have been stumbling you can't have been stumbling he can't have been stumbling we can't have been stumbling you can't have been stumbling they can't have been stumbling

Interrogative form

Simple form	V-ing form
can I stumble? can you stumble? can he stumble? can we stumble? can you stumble? can they stumble?	can I be stumbling? can you be stumbling? can he be stumbling? can we be stumbling? can you be stumbling? can they be stumbling?
Perfect	V-ing perfect
can I have stumbled? can you have stumbled? can he have stumbled? can we have stumbled? can you have stumbled? can they have stumbled?	can I have been stumbling? can you have been stumbling? can he have been stumbling? can we have been stumbling? can you have been stumbling? can they have been stumbling?

Interro-negative form

Simple form	V-ing form
can't I stumble? can't you stumble? can't he stumble? can't we stumble? can't you stumble? can't they stumble?	can't I be stumbling? can't you be stumbling? can't he be stumbling? can't we be stumbling? can't you be stumbling? can't they be stumbling?
Perfect	V-ing perfect
can't I have stumbled? can't you have stumbled? can't he have stumbled? can't we have stumbled? can't you have stumbled? can't they have stumbled?	can't I have been stumbling? can't you have been stumbling? can't he have been stumbling? can't we have been stumbling? can't you have been stumbling? can't they have been stumbling?