I can bumble you can bumble he can bumble we can bumble you can bumble they can bumble
V-ing form
I can be bumbling you can be bumbling he can be bumbling we can be bumbling you can be bumbling they can be bumbling
Perfect
I can have bumbled you can have bumbled he can have bumbled we can have bumbled you can have bumbled they can have bumbled
V-ing perfect
I can have been bumbling you can have been bumbling he can have been bumbling we can have been bumbling you can have been bumbling they can have been bumbling
Negation
Simple form
I can't bumble you can't bumble he can't bumble we can't bumble you can't bumble they can't bumble
V-ing form
I can't be bumbling you can't be bumbling he can't be bumbling we can't be bumbling you can't be bumbling they can't be bumbling
Perfect
I can't have bumbled you can't have bumbled he can't have bumbled we can't have bumbled you can't have bumbled they can't have bumbled
V-ing perfect
I can't have been bumbling you can't have been bumbling he can't have been bumbling we can't have been bumbling you can't have been bumbling they can't have been bumbling
Interrogative form
Simple form
can I bumble? can you bumble? can he bumble? can we bumble? can you bumble? can they bumble?
V-ing form
can I be bumbling? can you be bumbling? can he be bumbling? can we be bumbling? can you be bumbling? can they be bumbling?
Perfect
can I have bumbled? can you have bumbled? can he have bumbled? can we have bumbled? can you have bumbled? can they have bumbled?
V-ing perfect
can I have been bumbling? can you have been bumbling? can he have been bumbling? can we have been bumbling? can you have been bumbling? can they have been bumbling?
Interro-negative form
Simple form
can't I bumble? can't you bumble? can't he bumble? can't we bumble? can't you bumble? can't they bumble?
V-ing form
can't I be bumbling? can't you be bumbling? can't he be bumbling? can't we be bumbling? can't you be bumbling? can't they be bumbling?
Perfect
can't I have bumbled? can't you have bumbled? can't he have bumbled? can't we have bumbled? can't you have bumbled? can't they have bumbled?
V-ing perfect
can't I have been bumbling? can't you have been bumbling? can't he have been bumbling? can't we have been bumbling? can't you have been bumbling? can't they have been bumbling?