Regular verb: establish - established - established
Affirmation
Simple form
I could establish you could establish she could establish we could establish you could establish they could establish
V-ing form
I could be establishing you could be establishing she could be establishing we could be establishing you could be establishing they could be establishing
Perfect
I could have established you could have established she could have established we could have established you could have established they could have established
V-ing perfect
I could have been establishing you could have been establishing she could have been establishing we could have been establishing you could have been establishing they could have been establishing
Negation
Simple form
I couldn't establish you couldn't establish she couldn't establish we couldn't establish you couldn't establish they couldn't establish
V-ing form
I couldn't be establishing you couldn't be establishing she couldn't be establishing we couldn't be establishing you couldn't be establishing they couldn't be establishing
Perfect
I couldn't have established you couldn't have established she couldn't have established we couldn't have established you couldn't have established they couldn't have established
V-ing perfect
I couldn't have been establishing you couldn't have been establishing she couldn't have been establishing we couldn't have been establishing you couldn't have been establishing they couldn't have been establishing
Interrogative form
Simple form
could I establish? could you establish? could she establish? could we establish? could you establish? could they establish?
V-ing form
could I be establishing? could you be establishing? could she be establishing? could we be establishing? could you be establishing? could they be establishing?
Perfect
could I have established? could you have established? could she have established? could we have established? could you have established? could they have established?
V-ing perfect
could I have been establishing? could you have been establishing? could she have been establishing? could we have been establishing? could you have been establishing? could they have been establishing?
Interro-negative form
Simple form
couldn't I establish? couldn't you establish? couldn't she establish? couldn't we establish? couldn't you establish? couldn't they establish?
V-ing form
couldn't I be establishing? couldn't you be establishing? couldn't she be establishing? couldn't we be establishing? couldn't you be establishing? couldn't they be establishing?
Perfect
couldn't I have established? couldn't you have established? couldn't she have established? couldn't we have established? couldn't you have established? couldn't they have established?
V-ing perfect
couldn't I have been establishing? couldn't you have been establishing? couldn't she have been establishing? couldn't we have been establishing? couldn't you have been establishing? couldn't they have been establishing?