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