I can seek you can seek he can seek we can seek you can seek they can seek
V-ing form
I can be seeking you can be seeking he can be seeking we can be seeking you can be seeking they can be seeking
Perfect
I can have sought you can have sought he can have sought we can have sought you can have sought they can have sought
V-ing perfect
I can have been seeking you can have been seeking he can have been seeking we can have been seeking you can have been seeking they can have been seeking
Negation
Simple form
I can't seek you can't seek he can't seek we can't seek you can't seek they can't seek
V-ing form
I can't be seeking you can't be seeking he can't be seeking we can't be seeking you can't be seeking they can't be seeking
Perfect
I can't have sought you can't have sought he can't have sought we can't have sought you can't have sought they can't have sought
V-ing perfect
I can't have been seeking you can't have been seeking he can't have been seeking we can't have been seeking you can't have been seeking they can't have been seeking
Interrogative form
Simple form
can I seek? can you seek? can he seek? can we seek? can you seek? can they seek?
V-ing form
can I be seeking? can you be seeking? can he be seeking? can we be seeking? can you be seeking? can they be seeking?
Perfect
can I have sought? can you have sought? can he have sought? can we have sought? can you have sought? can they have sought?
V-ing perfect
can I have been seeking? can you have been seeking? can he have been seeking? can we have been seeking? can you have been seeking? can they have been seeking?
Interro-negative form
Simple form
can't I seek? can't you seek? can't he seek? can't we seek? can't you seek? can't they seek?
V-ing form
can't I be seeking? can't you be seeking? can't he be seeking? can't we be seeking? can't you be seeking? can't they be seeking?
Perfect
can't I have sought? can't you have sought? can't he have sought? can't we have sought? can't you have sought? can't they have sought?
V-ing perfect
can't I have been seeking? can't you have been seeking? can't he have been seeking? can't we have been seeking? can't you have been seeking? can't they have been seeking?