I can burl you can burl he can burl we can burl you can burl they can burl
V-ing form
I can be burling you can be burling he can be burling we can be burling you can be burling they can be burling
Perfect
I can have burled you can have burled he can have burled we can have burled you can have burled they can have burled
V-ing perfect
I can have been burling you can have been burling he can have been burling we can have been burling you can have been burling they can have been burling
Negation
Simple form
I cannot burl you cannot burl he cannot burl we cannot burl you cannot burl they cannot burl
V-ing form
I cannot be burling you cannot be burling he cannot be burling we cannot be burling you cannot be burling they cannot be burling
Perfect
I cannot have burled you cannot have burled he cannot have burled we cannot have burled you cannot have burled they cannot have burled
V-ing perfect
I cannot have been burling you cannot have been burling he cannot have been burling we cannot have been burling you cannot have been burling they cannot have been burling
Interrogative form
Simple form
can I burl? can you burl? can he burl? can we burl? can you burl? can they burl?
V-ing form
can I be burling? can you be burling? can he be burling? can we be burling? can you be burling? can they be burling?
Perfect
can I have burled? can you have burled? can he have burled? can we have burled? can you have burled? can they have burled?
V-ing perfect
can I have been burling? can you have been burling? can he have been burling? can we have been burling? can you have been burling? can they have been burling?
Interro-negative form
Simple form
can I not burl? can you not burl? can he not burl? can we not burl? can you not burl? can they not burl?
V-ing form
can I not be burling? can you not be burling? can he not be burling? can we not be burling? can you not be burling? can they not be burling?
Perfect
can I not have burled? can you not have burled? can he not have burled? can we not have burled? can you not have burled? can they not have burled?
V-ing perfect
can I not have been burling? can you not have been burling? can he not have been burling? can we not have been burling? can you not have been burling? can they not have been burling?