English verb conjugation
COULD YARN

Regular verb: yarn - yarned - yarned

Affirmation

Simple form	V-ing form
I could yarn you could yarn he could yarn we could yarn you could yarn they could yarn	I could be yarning you could be yarning he could be yarning we could be yarning you could be yarning they could be yarning
Perfect	V-ing perfect
I could have yarned you could have yarned he could have yarned we could have yarned you could have yarned they could have yarned	I could have been yarning you could have been yarning he could have been yarning we could have been yarning you could have been yarning they could have been yarning

Negation

Simple form	V-ing form
I couldn't yarn you couldn't yarn he couldn't yarn we couldn't yarn you couldn't yarn they couldn't yarn	I couldn't be yarning you couldn't be yarning he couldn't be yarning we couldn't be yarning you couldn't be yarning they couldn't be yarning
Perfect	V-ing perfect
I couldn't have yarned you couldn't have yarned he couldn't have yarned we couldn't have yarned you couldn't have yarned they couldn't have yarned	I couldn't have been yarning you couldn't have been yarning he couldn't have been yarning we couldn't have been yarning you couldn't have been yarning they couldn't have been yarning

Interrogative form

Simple form	V-ing form
could I yarn? could you yarn? could he yarn? could we yarn? could you yarn? could they yarn?	could I be yarning? could you be yarning? could he be yarning? could we be yarning? could you be yarning? could they be yarning?
Perfect	V-ing perfect
could I have yarned? could you have yarned? could he have yarned? could we have yarned? could you have yarned? could they have yarned?	could I have been yarning? could you have been yarning? could he have been yarning? could we have been yarning? could you have been yarning? could they have been yarning?

Interro-negative form

Simple form	V-ing form
couldn't I yarn? couldn't you yarn? couldn't he yarn? couldn't we yarn? couldn't you yarn? couldn't they yarn?	couldn't I be yarning? couldn't you be yarning? couldn't he be yarning? couldn't we be yarning? couldn't you be yarning? couldn't they be yarning?
Perfect	V-ing perfect
couldn't I have yarned? couldn't you have yarned? couldn't he have yarned? couldn't we have yarned? couldn't you have yarned? couldn't they have yarned?	couldn't I have been yarning? couldn't you have been yarning? couldn't he have been yarning? couldn't we have been yarning? couldn't you have been yarning? couldn't they have been yarning?