I can flush you can flush he can flush we can flush you can flush they can flush
V-ing form
I can be flushing you can be flushing he can be flushing we can be flushing you can be flushing they can be flushing
Perfect
I can have flushed you can have flushed he can have flushed we can have flushed you can have flushed they can have flushed
V-ing perfect
I can have been flushing you can have been flushing he can have been flushing we can have been flushing you can have been flushing they can have been flushing
Negation
Simple form
I can't flush you can't flush he can't flush we can't flush you can't flush they can't flush
V-ing form
I can't be flushing you can't be flushing he can't be flushing we can't be flushing you can't be flushing they can't be flushing
Perfect
I can't have flushed you can't have flushed he can't have flushed we can't have flushed you can't have flushed they can't have flushed
V-ing perfect
I can't have been flushing you can't have been flushing he can't have been flushing we can't have been flushing you can't have been flushing they can't have been flushing
Interrogative form
Simple form
can I flush? can you flush? can he flush? can we flush? can you flush? can they flush?
V-ing form
can I be flushing? can you be flushing? can he be flushing? can we be flushing? can you be flushing? can they be flushing?
Perfect
can I have flushed? can you have flushed? can he have flushed? can we have flushed? can you have flushed? can they have flushed?
V-ing perfect
can I have been flushing? can you have been flushing? can he have been flushing? can we have been flushing? can you have been flushing? can they have been flushing?
Interro-negative form
Simple form
can't I flush? can't you flush? can't he flush? can't we flush? can't you flush? can't they flush?
V-ing form
can't I be flushing? can't you be flushing? can't he be flushing? can't we be flushing? can't you be flushing? can't they be flushing?
Perfect
can't I have flushed? can't you have flushed? can't he have flushed? can't we have flushed? can't you have flushed? can't they have flushed?
V-ing perfect
can't I have been flushing? can't you have been flushing? can't he have been flushing? can't we have been flushing? can't you have been flushing? can't they have been flushing?