English verb conjugation
COULD CLATTER

Regular verb: clatter - clattered - clattered

Affirmation

Simple form	V-ing form
I could clatter you could clatter he could clatter we could clatter you could clatter they could clatter	I could be clattering you could be clattering he could be clattering we could be clattering you could be clattering they could be clattering
Perfect	V-ing perfect
I could have clattered you could have clattered he could have clattered we could have clattered you could have clattered they could have clattered	I could have been clattering you could have been clattering he could have been clattering we could have been clattering you could have been clattering they could have been clattering

Negation

Simple form	V-ing form
I couldn't clatter you couldn't clatter he couldn't clatter we couldn't clatter you couldn't clatter they couldn't clatter	I couldn't be clattering you couldn't be clattering he couldn't be clattering we couldn't be clattering you couldn't be clattering they couldn't be clattering
Perfect	V-ing perfect
I couldn't have clattered you couldn't have clattered he couldn't have clattered we couldn't have clattered you couldn't have clattered they couldn't have clattered	I couldn't have been clattering you couldn't have been clattering he couldn't have been clattering we couldn't have been clattering you couldn't have been clattering they couldn't have been clattering

Interrogative form

Simple form	V-ing form
could I clatter? could you clatter? could he clatter? could we clatter? could you clatter? could they clatter?	could I be clattering? could you be clattering? could he be clattering? could we be clattering? could you be clattering? could they be clattering?
Perfect	V-ing perfect
could I have clattered? could you have clattered? could he have clattered? could we have clattered? could you have clattered? could they have clattered?	could I have been clattering? could you have been clattering? could he have been clattering? could we have been clattering? could you have been clattering? could they have been clattering?

Interro-negative form

Simple form	V-ing form
couldn't I clatter? couldn't you clatter? couldn't he clatter? couldn't we clatter? couldn't you clatter? couldn't they clatter?	couldn't I be clattering? couldn't you be clattering? couldn't he be clattering? couldn't we be clattering? couldn't you be clattering? couldn't they be clattering?
Perfect	V-ing perfect
couldn't I have clattered? couldn't you have clattered? couldn't he have clattered? couldn't we have clattered? couldn't you have clattered? couldn't they have clattered?	couldn't I have been clattering? couldn't you have been clattering? couldn't he have been clattering? couldn't we have been clattering? couldn't you have been clattering? couldn't they have been clattering?