I could instant-message you could instant-message he could instant-message we could instant-message you could instant-message they could instant-message
V-ing form
I could be instant-messaging you could be instant-messaging he could be instant-messaging we could be instant-messaging you could be instant-messaging they could be instant-messaging
Perfect
I could have instant-messaged you could have instant-messaged he could have instant-messaged we could have instant-messaged you could have instant-messaged they could have instant-messaged
V-ing perfect
I could have been instant-messaging you could have been instant-messaging he could have been instant-messaging we could have been instant-messaging you could have been instant-messaging they could have been instant-messaging
Negation
Simple form
I couldn't instant-message you couldn't instant-message he couldn't instant-message we couldn't instant-message you couldn't instant-message they couldn't instant-message
V-ing form
I couldn't be instant-messaging you couldn't be instant-messaging he couldn't be instant-messaging we couldn't be instant-messaging you couldn't be instant-messaging they couldn't be instant-messaging
Perfect
I couldn't have instant-messaged you couldn't have instant-messaged he couldn't have instant-messaged we couldn't have instant-messaged you couldn't have instant-messaged they couldn't have instant-messaged
V-ing perfect
I couldn't have been instant-messaging you couldn't have been instant-messaging he couldn't have been instant-messaging we couldn't have been instant-messaging you couldn't have been instant-messaging they couldn't have been instant-messaging
Interrogative form
Simple form
could I instant-message? could you instant-message? could he instant-message? could we instant-message? could you instant-message? could they instant-message?
V-ing form
could I be instant-messaging? could you be instant-messaging? could he be instant-messaging? could we be instant-messaging? could you be instant-messaging? could they be instant-messaging?
Perfect
could I have instant-messaged? could you have instant-messaged? could he have instant-messaged? could we have instant-messaged? could you have instant-messaged? could they have instant-messaged?
V-ing perfect
could I have been instant-messaging? could you have been instant-messaging? could he have been instant-messaging? could we have been instant-messaging? could you have been instant-messaging? could they have been instant-messaging?
Interro-negative form
Simple form
couldn't I instant-message? couldn't you instant-message? couldn't he instant-message? couldn't we instant-message? couldn't you instant-message? couldn't they instant-message?
V-ing form
couldn't I be instant-messaging? couldn't you be instant-messaging? couldn't he be instant-messaging? couldn't we be instant-messaging? couldn't you be instant-messaging? couldn't they be instant-messaging?
Perfect
couldn't I have instant-messaged? couldn't you have instant-messaged? couldn't he have instant-messaged? couldn't we have instant-messaged? couldn't you have instant-messaged? couldn't they have instant-messaged?
V-ing perfect
couldn't I have been instant-messaging? couldn't you have been instant-messaging? couldn't he have been instant-messaging? couldn't we have been instant-messaging? couldn't you have been instant-messaging? couldn't they have been instant-messaging?