I can append you can append she can append we can append you can append they can append
V-ing form
I can be appending you can be appending she can be appending we can be appending you can be appending they can be appending
Perfect
I can have appended you can have appended she can have appended we can have appended you can have appended they can have appended
V-ing perfect
I can have been appending you can have been appending she can have been appending we can have been appending you can have been appending they can have been appending
Negation
Simple form
I can't append you can't append she can't append we can't append you can't append they can't append
V-ing form
I can't be appending you can't be appending she can't be appending we can't be appending you can't be appending they can't be appending
Perfect
I can't have appended you can't have appended she can't have appended we can't have appended you can't have appended they can't have appended
V-ing perfect
I can't have been appending you can't have been appending she can't have been appending we can't have been appending you can't have been appending they can't have been appending
Interrogative form
Simple form
can I append? can you append? can she append? can we append? can you append? can they append?
V-ing form
can I be appending? can you be appending? can she be appending? can we be appending? can you be appending? can they be appending?
Perfect
can I have appended? can you have appended? can she have appended? can we have appended? can you have appended? can they have appended?
V-ing perfect
can I have been appending? can you have been appending? can she have been appending? can we have been appending? can you have been appending? can they have been appending?
Interro-negative form
Simple form
can't I append? can't you append? can't she append? can't we append? can't you append? can't they append?
V-ing form
can't I be appending? can't you be appending? can't she be appending? can't we be appending? can't you be appending? can't they be appending?
Perfect
can't I have appended? can't you have appended? can't she have appended? can't we have appended? can't you have appended? can't they have appended?
V-ing perfect
can't I have been appending? can't you have been appending? can't she have been appending? can't we have been appending? can't you have been appending? can't they have been appending?