I can index you can index he can index we can index you can index they can index
V-ing form
I can be indexing you can be indexing he can be indexing we can be indexing you can be indexing they can be indexing
Perfect
I can have indexed you can have indexed he can have indexed we can have indexed you can have indexed they can have indexed
V-ing perfect
I can have been indexing you can have been indexing he can have been indexing we can have been indexing you can have been indexing they can have been indexing
Negation
Simple form
I cannot index you cannot index he cannot index we cannot index you cannot index they cannot index
V-ing form
I cannot be indexing you cannot be indexing he cannot be indexing we cannot be indexing you cannot be indexing they cannot be indexing
Perfect
I cannot have indexed you cannot have indexed he cannot have indexed we cannot have indexed you cannot have indexed they cannot have indexed
V-ing perfect
I cannot have been indexing you cannot have been indexing he cannot have been indexing we cannot have been indexing you cannot have been indexing they cannot have been indexing
Interrogative form
Simple form
can I index? can you index? can he index? can we index? can you index? can they index?
V-ing form
can I be indexing? can you be indexing? can he be indexing? can we be indexing? can you be indexing? can they be indexing?
Perfect
can I have indexed? can you have indexed? can he have indexed? can we have indexed? can you have indexed? can they have indexed?
V-ing perfect
can I have been indexing? can you have been indexing? can he have been indexing? can we have been indexing? can you have been indexing? can they have been indexing?
Interro-negative form
Simple form
can I not index? can you not index? can he not index? can we not index? can you not index? can they not index?
V-ing form
can I not be indexing? can you not be indexing? can he not be indexing? can we not be indexing? can you not be indexing? can they not be indexing?
Perfect
can I not have indexed? can you not have indexed? can he not have indexed? can we not have indexed? can you not have indexed? can they not have indexed?
V-ing perfect
can I not have been indexing? can you not have been indexing? can he not have been indexing? can we not have been indexing? can you not have been indexing? can they not have been indexing?