I can mumble you can mumble he can mumble we can mumble you can mumble they can mumble
V-ing form
I can be mumbling you can be mumbling he can be mumbling we can be mumbling you can be mumbling they can be mumbling
Perfect
I can have mumbled you can have mumbled he can have mumbled we can have mumbled you can have mumbled they can have mumbled
V-ing perfect
I can have been mumbling you can have been mumbling he can have been mumbling we can have been mumbling you can have been mumbling they can have been mumbling
Negation
Simple form
I can't mumble you can't mumble he can't mumble we can't mumble you can't mumble they can't mumble
V-ing form
I can't be mumbling you can't be mumbling he can't be mumbling we can't be mumbling you can't be mumbling they can't be mumbling
Perfect
I can't have mumbled you can't have mumbled he can't have mumbled we can't have mumbled you can't have mumbled they can't have mumbled
V-ing perfect
I can't have been mumbling you can't have been mumbling he can't have been mumbling we can't have been mumbling you can't have been mumbling they can't have been mumbling
Interrogative form
Simple form
can I mumble? can you mumble? can he mumble? can we mumble? can you mumble? can they mumble?
V-ing form
can I be mumbling? can you be mumbling? can he be mumbling? can we be mumbling? can you be mumbling? can they be mumbling?
Perfect
can I have mumbled? can you have mumbled? can he have mumbled? can we have mumbled? can you have mumbled? can they have mumbled?
V-ing perfect
can I have been mumbling? can you have been mumbling? can he have been mumbling? can we have been mumbling? can you have been mumbling? can they have been mumbling?
Interro-negative form
Simple form
can't I mumble? can't you mumble? can't he mumble? can't we mumble? can't you mumble? can't they mumble?
V-ing form
can't I be mumbling? can't you be mumbling? can't he be mumbling? can't we be mumbling? can't you be mumbling? can't they be mumbling?
Perfect
can't I have mumbled? can't you have mumbled? can't he have mumbled? can't we have mumbled? can't you have mumbled? can't they have mumbled?
V-ing perfect
can't I have been mumbling? can't you have been mumbling? can't he have been mumbling? can't we have been mumbling? can't you have been mumbling? can't they have been mumbling?