English verb conjugation
COULD APPEND

Regular verb: append - appended - appended

Affirmation

Simple form	V-ing form
I could append you could append she could append we could append you could append they could append	I could be appending you could be appending she could be appending we could be appending you could be appending they could be appending
Perfect	V-ing perfect
I could have appended you could have appended she could have appended we could have appended you could have appended they could have appended	I could have been appending you could have been appending she could have been appending we could have been appending you could have been appending they could have been appending

Negation

Simple form	V-ing form
I couldn't append you couldn't append she couldn't append we couldn't append you couldn't append they couldn't append	I couldn't be appending you couldn't be appending she couldn't be appending we couldn't be appending you couldn't be appending they couldn't be appending
Perfect	V-ing perfect
I couldn't have appended you couldn't have appended she couldn't have appended we couldn't have appended you couldn't have appended they couldn't have appended	I couldn't have been appending you couldn't have been appending she couldn't have been appending we couldn't have been appending you couldn't have been appending they couldn't have been appending

Interrogative form

Simple form	V-ing form
could I append? could you append? could she append? could we append? could you append? could they append?	could I be appending? could you be appending? could she be appending? could we be appending? could you be appending? could they be appending?
Perfect	V-ing perfect
could I have appended? could you have appended? could she have appended? could we have appended? could you have appended? could they have appended?	could I have been appending? could you have been appending? could she have been appending? could we have been appending? could you have been appending? could they have been appending?

Interro-negative form

Simple form	V-ing form
couldn't I append? couldn't you append? couldn't she append? couldn't we append? couldn't you append? couldn't they append?	couldn't I be appending? couldn't you be appending? couldn't she be appending? couldn't we be appending? couldn't you be appending? couldn't they be appending?
Perfect	V-ing perfect
couldn't I have appended? couldn't you have appended? couldn't she have appended? couldn't we have appended? couldn't you have appended? couldn't they have appended?	couldn't I have been appending? couldn't you have been appending? couldn't she have been appending? couldn't we have been appending? couldn't you have been appending? couldn't they have been appending?