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