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