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