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 can't appear you can't appear he can't appear we can't appear you can't appear they can't appear
V-ing form
I can't be appearing you can't be appearing he can't be appearing we can't be appearing you can't be appearing they can't be appearing
Perfect
I can't have appeared you can't have appeared he can't have appeared we can't have appeared you can't have appeared they can't have appeared
V-ing perfect
I can't have been appearing you can't have been appearing he can't have been appearing we can't have been appearing you can't have been appearing they can't 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't I appear? can't you appear? can't he appear? can't we appear? can't you appear? can't they appear?
V-ing form
can't I be appearing? can't you be appearing? can't he be appearing? can't we be appearing? can't you be appearing? can't they be appearing?
Perfect
can't I have appeared? can't you have appeared? can't he have appeared? can't we have appeared? can't you have appeared? can't they have appeared?
V-ing perfect
can't I have been appearing? can't you have been appearing? can't he have been appearing? can't we have been appearing? can't you have been appearing? can't they have been appearing?