English verb conjugation
COULD DESTABILISE

Regular verb: destabilise - destabilised - destabilised

Affirmation

Simple form	V-ing form
I could destabilise you could destabilise he could destabilise we could destabilise you could destabilise they could destabilise	I could be destabilising you could be destabilising he could be destabilising we could be destabilising you could be destabilising they could be destabilising
Perfect	V-ing perfect
I could have destabilised you could have destabilised he could have destabilised we could have destabilised you could have destabilised they could have destabilised	I could have been destabilising you could have been destabilising he could have been destabilising we could have been destabilising you could have been destabilising they could have been destabilising

Negation

Simple form	V-ing form
I couldn't destabilise you couldn't destabilise he couldn't destabilise we couldn't destabilise you couldn't destabilise they couldn't destabilise	I couldn't be destabilising you couldn't be destabilising he couldn't be destabilising we couldn't be destabilising you couldn't be destabilising they couldn't be destabilising
Perfect	V-ing perfect
I couldn't have destabilised you couldn't have destabilised he couldn't have destabilised we couldn't have destabilised you couldn't have destabilised they couldn't have destabilised	I couldn't have been destabilising you couldn't have been destabilising he couldn't have been destabilising we couldn't have been destabilising you couldn't have been destabilising they couldn't have been destabilising

Interrogative form

Simple form	V-ing form
could I destabilise? could you destabilise? could he destabilise? could we destabilise? could you destabilise? could they destabilise?	could I be destabilising? could you be destabilising? could he be destabilising? could we be destabilising? could you be destabilising? could they be destabilising?
Perfect	V-ing perfect
could I have destabilised? could you have destabilised? could he have destabilised? could we have destabilised? could you have destabilised? could they have destabilised?	could I have been destabilising? could you have been destabilising? could he have been destabilising? could we have been destabilising? could you have been destabilising? could they have been destabilising?

Interro-negative form

Simple form	V-ing form
couldn't I destabilise? couldn't you destabilise? couldn't he destabilise? couldn't we destabilise? couldn't you destabilise? couldn't they destabilise?	couldn't I be destabilising? couldn't you be destabilising? couldn't he be destabilising? couldn't we be destabilising? couldn't you be destabilising? couldn't they be destabilising?
Perfect	V-ing perfect
couldn't I have destabilised? couldn't you have destabilised? couldn't he have destabilised? couldn't we have destabilised? couldn't you have destabilised? couldn't they have destabilised?	couldn't I have been destabilising? couldn't you have been destabilising? couldn't he have been destabilising? couldn't we have been destabilising? couldn't you have been destabilising? couldn't they have been destabilising?