I can appear you can appear he can appear we can appear you can appear they can appear
V-ing form
I can be appearing you can be appearing he can be appearing we can be appearing you can be appearing they can be appearing
Perfect
I can have appeared you can have appeared he can have appeared we can have appeared you can have appeared they can have appeared
V-ing perfect
I can have been appearing you can have been appearing he can have been appearing we can have been appearing you can have been appearing they can have been appearing
Negation
Simple form
I cannot appear you cannot appear he cannot appear we cannot appear you cannot appear they cannot appear
V-ing form
I cannot be appearing you cannot be appearing he cannot be appearing we cannot be appearing you cannot be appearing they cannot be appearing
Perfect
I cannot have appeared you cannot have appeared he cannot have appeared we cannot have appeared you cannot have appeared they cannot have appeared
V-ing perfect
I cannot have been appearing you cannot have been appearing he cannot have been appearing we cannot have been appearing you cannot have been appearing they cannot have been appearing
Interrogative form
Simple form
can I appear? can you appear? can he appear? can we appear? can you appear? can they appear?
V-ing form
can I be appearing? can you be appearing? can he be appearing? can we be appearing? can you be appearing? can they be appearing?
Perfect
can I have appeared? can you have appeared? can he have appeared? can we have appeared? can you have appeared? can they have appeared?
V-ing perfect
can I have been appearing? can you have been appearing? can he have been appearing? can we have been appearing? can you have been appearing? can they have been appearing?
Interro-negative form
Simple form
can I not appear? can you not appear? can he not appear? can we not appear? can you not appear? can they not appear?
V-ing form
can I not be appearing? can you not be appearing? can he not be appearing? can we not be appearing? can you not be appearing? can they not be appearing?
Perfect
can I not have appeared? can you not have appeared? can he not have appeared? can we not have appeared? can you not have appeared? can they not have appeared?
V-ing perfect
can I not have been appearing? can you not have been appearing? can he not have been appearing? can we not have been appearing? can you not have been appearing? can they not have been appearing?