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