English verb conjugation
COULD CRYSTALLISE

Regular verb: crystallise - crystallised - crystallised

Affirmation

Simple form	V-ing form
I could crystallise you could crystallise he could crystallise we could crystallise you could crystallise they could crystallise	I could be crystallising you could be crystallising he could be crystallising we could be crystallising you could be crystallising they could be crystallising
Perfect	V-ing perfect
I could have crystallised you could have crystallised he could have crystallised we could have crystallised you could have crystallised they could have crystallised	I could have been crystallising you could have been crystallising he could have been crystallising we could have been crystallising you could have been crystallising they could have been crystallising

Negation

Simple form	V-ing form
I couldn't crystallise you couldn't crystallise he couldn't crystallise we couldn't crystallise you couldn't crystallise they couldn't crystallise	I couldn't be crystallising you couldn't be crystallising he couldn't be crystallising we couldn't be crystallising you couldn't be crystallising they couldn't be crystallising
Perfect	V-ing perfect
I couldn't have crystallised you couldn't have crystallised he couldn't have crystallised we couldn't have crystallised you couldn't have crystallised they couldn't have crystallised	I couldn't have been crystallising you couldn't have been crystallising he couldn't have been crystallising we couldn't have been crystallising you couldn't have been crystallising they couldn't have been crystallising

Interrogative form

Simple form	V-ing form
could I crystallise? could you crystallise? could he crystallise? could we crystallise? could you crystallise? could they crystallise?	could I be crystallising? could you be crystallising? could he be crystallising? could we be crystallising? could you be crystallising? could they be crystallising?
Perfect	V-ing perfect
could I have crystallised? could you have crystallised? could he have crystallised? could we have crystallised? could you have crystallised? could they have crystallised?	could I have been crystallising? could you have been crystallising? could he have been crystallising? could we have been crystallising? could you have been crystallising? could they have been crystallising?

Interro-negative form

Simple form	V-ing form
couldn't I crystallise? couldn't you crystallise? couldn't he crystallise? couldn't we crystallise? couldn't you crystallise? couldn't they crystallise?	couldn't I be crystallising? couldn't you be crystallising? couldn't he be crystallising? couldn't we be crystallising? couldn't you be crystallising? couldn't they be crystallising?
Perfect	V-ing perfect
couldn't I have crystallised? couldn't you have crystallised? couldn't he have crystallised? couldn't we have crystallised? couldn't you have crystallised? couldn't they have crystallised?	couldn't I have been crystallising? couldn't you have been crystallising? couldn't he have been crystallising? couldn't we have been crystallising? couldn't you have been crystallising? couldn't they have been crystallising?