I could appear you could appear he could appear we could appear you could appear they could appear
Forma con V-ing
I could be appearing you could be appearing he could be appearing we could be appearing you could be appearing they could be appearing
Perfecto
I could have appeared you could have appeared he could have appeared we could have appeared you could have appeared they could have appeared
Perfecto con V-ing
I could have been appearing you could have been appearing he could have been appearing we could have been appearing you could have been appearing they could have been appearing
Negación
Forma simple
I couldn't appear you couldn't appear he couldn't appear we couldn't appear you couldn't appear they couldn't appear
Forma con V-ing
I couldn't be appearing you couldn't be appearing he couldn't be appearing we couldn't be appearing you couldn't be appearing they couldn't be appearing
Perfecto
I couldn't have appeared you couldn't have appeared he couldn't have appeared we couldn't have appeared you couldn't have appeared they couldn't have appeared
Perfecto con V-ing
I couldn't have been appearing you couldn't have been appearing he couldn't have been appearing we couldn't have been appearing you couldn't have been appearing they couldn't have been appearing
Forma interrogativa
Forma simple
could I appear? could you appear? could he appear? could we appear? could you appear? could they appear?
Forma con V-ing
could I be appearing? could you be appearing? could he be appearing? could we be appearing? could you be appearing? could they be appearing?
Perfecto
could I have appeared? could you have appeared? could he have appeared? could we have appeared? could you have appeared? could they have appeared?
Perfecto con V-ing
could I have been appearing? could you have been appearing? could he have been appearing? could we have been appearing? could you have been appearing? could they have been appearing?
Forma interro-negativa
Forma simple
couldn't I appear? couldn't you appear? couldn't he appear? couldn't we appear? couldn't you appear? couldn't they appear?
Forma con V-ing
couldn't I be appearing? couldn't you be appearing? couldn't he be appearing? couldn't we be appearing? couldn't you be appearing? couldn't they be appearing?
Perfecto
couldn't I have appeared? couldn't you have appeared? couldn't he have appeared? couldn't we have appeared? couldn't you have appeared? couldn't they have appeared?
Perfecto con V-ing
couldn't I have been appearing? couldn't you have been appearing? couldn't he have been appearing? couldn't we have been appearing? couldn't you have been appearing? couldn't they have been appearing?