English verb conjugation
COULD INDEX

Regular verb: index - indexed - indexed

Affirmation

Simple form	V-ing form
I could index you could index she could index we could index you could index they could index	I could be indexing you could be indexing she could be indexing we could be indexing you could be indexing they could be indexing
Perfect	V-ing perfect
I could have indexed you could have indexed she could have indexed we could have indexed you could have indexed they could have indexed	I could have been indexing you could have been indexing she could have been indexing we could have been indexing you could have been indexing they could have been indexing

Negation

Simple form	V-ing form
I couldn't index you couldn't index she couldn't index we couldn't index you couldn't index they couldn't index	I couldn't be indexing you couldn't be indexing she couldn't be indexing we couldn't be indexing you couldn't be indexing they couldn't be indexing
Perfect	V-ing perfect
I couldn't have indexed you couldn't have indexed she couldn't have indexed we couldn't have indexed you couldn't have indexed they couldn't have indexed	I couldn't have been indexing you couldn't have been indexing she couldn't have been indexing we couldn't have been indexing you couldn't have been indexing they couldn't have been indexing

Interrogative form

Simple form	V-ing form
could I index? could you index? could she index? could we index? could you index? could they index?	could I be indexing? could you be indexing? could she be indexing? could we be indexing? could you be indexing? could they be indexing?
Perfect	V-ing perfect
could I have indexed? could you have indexed? could she have indexed? could we have indexed? could you have indexed? could they have indexed?	could I have been indexing? could you have been indexing? could she have been indexing? could we have been indexing? could you have been indexing? could they have been indexing?

Interro-negative form

Simple form	V-ing form
couldn't I index? couldn't you index? couldn't she index? couldn't we index? couldn't you index? couldn't they index?	couldn't I be indexing? couldn't you be indexing? couldn't she be indexing? couldn't we be indexing? couldn't you be indexing? couldn't they be indexing?
Perfect	V-ing perfect
couldn't I have indexed? couldn't you have indexed? couldn't she have indexed? couldn't we have indexed? couldn't you have indexed? couldn't they have indexed?	couldn't I have been indexing? couldn't you have been indexing? couldn't she have been indexing? couldn't we have been indexing? couldn't you have been indexing? couldn't they have been indexing?