I could neigh you could neigh he could neigh we could neigh you could neigh they could neigh
V-ing form
I could be neighing you could be neighing he could be neighing we could be neighing you could be neighing they could be neighing
Perfect
I could have neighed you could have neighed he could have neighed we could have neighed you could have neighed they could have neighed
V-ing perfect
I could have been neighing you could have been neighing he could have been neighing we could have been neighing you could have been neighing they could have been neighing
Negation
Simple form
I couldn't neigh you couldn't neigh he couldn't neigh we couldn't neigh you couldn't neigh they couldn't neigh
V-ing form
I couldn't be neighing you couldn't be neighing he couldn't be neighing we couldn't be neighing you couldn't be neighing they couldn't be neighing
Perfect
I couldn't have neighed you couldn't have neighed he couldn't have neighed we couldn't have neighed you couldn't have neighed they couldn't have neighed
V-ing perfect
I couldn't have been neighing you couldn't have been neighing he couldn't have been neighing we couldn't have been neighing you couldn't have been neighing they couldn't have been neighing
Interrogative form
Simple form
could I neigh? could you neigh? could he neigh? could we neigh? could you neigh? could they neigh?
V-ing form
could I be neighing? could you be neighing? could he be neighing? could we be neighing? could you be neighing? could they be neighing?
Perfect
could I have neighed? could you have neighed? could he have neighed? could we have neighed? could you have neighed? could they have neighed?
V-ing perfect
could I have been neighing? could you have been neighing? could he have been neighing? could we have been neighing? could you have been neighing? could they have been neighing?
Interro-negative form
Simple form
couldn't I neigh? couldn't you neigh? couldn't he neigh? couldn't we neigh? couldn't you neigh? couldn't they neigh?
V-ing form
couldn't I be neighing? couldn't you be neighing? couldn't he be neighing? couldn't we be neighing? couldn't you be neighing? couldn't they be neighing?
Perfect
couldn't I have neighed? couldn't you have neighed? couldn't he have neighed? couldn't we have neighed? couldn't you have neighed? couldn't they have neighed?
V-ing perfect
couldn't I have been neighing? couldn't you have been neighing? couldn't he have been neighing? couldn't we have been neighing? couldn't you have been neighing? couldn't they have been neighing?