English verb conjugation
COULD MORTISE

Regular verb: mortise - mortised - mortised

Affirmation

Simple form	V-ing form
I could mortise you could mortise he could mortise we could mortise you could mortise they could mortise	I could be mortising you could be mortising he could be mortising we could be mortising you could be mortising they could be mortising
Perfect	V-ing perfect
I could have mortised you could have mortised he could have mortised we could have mortised you could have mortised they could have mortised	I could have been mortising you could have been mortising he could have been mortising we could have been mortising you could have been mortising they could have been mortising

Negation

Simple form	V-ing form
I couldn't mortise you couldn't mortise he couldn't mortise we couldn't mortise you couldn't mortise they couldn't mortise	I couldn't be mortising you couldn't be mortising he couldn't be mortising we couldn't be mortising you couldn't be mortising they couldn't be mortising
Perfect	V-ing perfect
I couldn't have mortised you couldn't have mortised he couldn't have mortised we couldn't have mortised you couldn't have mortised they couldn't have mortised	I couldn't have been mortising you couldn't have been mortising he couldn't have been mortising we couldn't have been mortising you couldn't have been mortising they couldn't have been mortising

Interrogative form

Simple form	V-ing form
could I mortise? could you mortise? could he mortise? could we mortise? could you mortise? could they mortise?	could I be mortising? could you be mortising? could he be mortising? could we be mortising? could you be mortising? could they be mortising?
Perfect	V-ing perfect
could I have mortised? could you have mortised? could he have mortised? could we have mortised? could you have mortised? could they have mortised?	could I have been mortising? could you have been mortising? could he have been mortising? could we have been mortising? could you have been mortising? could they have been mortising?

Interro-negative form

Simple form	V-ing form
couldn't I mortise? couldn't you mortise? couldn't he mortise? couldn't we mortise? couldn't you mortise? couldn't they mortise?	couldn't I be mortising? couldn't you be mortising? couldn't he be mortising? couldn't we be mortising? couldn't you be mortising? couldn't they be mortising?
Perfect	V-ing perfect
couldn't I have mortised? couldn't you have mortised? couldn't he have mortised? couldn't we have mortised? couldn't you have mortised? couldn't they have mortised?	couldn't I have been mortising? couldn't you have been mortising? couldn't he have been mortising? couldn't we have been mortising? couldn't you have been mortising? couldn't they have been mortising?