English verb conjugation
COULD SHRILL

Regular verb: shrill - shrilled - shrilled

Affirmation

Simple form	V-ing form
I could shrill you could shrill he could shrill we could shrill you could shrill they could shrill	I could be shrilling you could be shrilling he could be shrilling we could be shrilling you could be shrilling they could be shrilling
Perfect	V-ing perfect
I could have shrilled you could have shrilled he could have shrilled we could have shrilled you could have shrilled they could have shrilled	I could have been shrilling you could have been shrilling he could have been shrilling we could have been shrilling you could have been shrilling they could have been shrilling

Negation

Simple form	V-ing form
I couldn't shrill you couldn't shrill he couldn't shrill we couldn't shrill you couldn't shrill they couldn't shrill	I couldn't be shrilling you couldn't be shrilling he couldn't be shrilling we couldn't be shrilling you couldn't be shrilling they couldn't be shrilling
Perfect	V-ing perfect
I couldn't have shrilled you couldn't have shrilled he couldn't have shrilled we couldn't have shrilled you couldn't have shrilled they couldn't have shrilled	I couldn't have been shrilling you couldn't have been shrilling he couldn't have been shrilling we couldn't have been shrilling you couldn't have been shrilling they couldn't have been shrilling

Interrogative form

Simple form	V-ing form
could I shrill? could you shrill? could he shrill? could we shrill? could you shrill? could they shrill?	could I be shrilling? could you be shrilling? could he be shrilling? could we be shrilling? could you be shrilling? could they be shrilling?
Perfect	V-ing perfect
could I have shrilled? could you have shrilled? could he have shrilled? could we have shrilled? could you have shrilled? could they have shrilled?	could I have been shrilling? could you have been shrilling? could he have been shrilling? could we have been shrilling? could you have been shrilling? could they have been shrilling?

Interro-negative form

Simple form	V-ing form
couldn't I shrill? couldn't you shrill? couldn't he shrill? couldn't we shrill? couldn't you shrill? couldn't they shrill?	couldn't I be shrilling? couldn't you be shrilling? couldn't he be shrilling? couldn't we be shrilling? couldn't you be shrilling? couldn't they be shrilling?
Perfect	V-ing perfect
couldn't I have shrilled? couldn't you have shrilled? couldn't he have shrilled? couldn't we have shrilled? couldn't you have shrilled? couldn't they have shrilled?	couldn't I have been shrilling? couldn't you have been shrilling? couldn't he have been shrilling? couldn't we have been shrilling? couldn't you have been shrilling? couldn't they have been shrilling?