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 could not shrill you could not shrill he could not shrill we could not shrill you could not shrill they could not shrill	I could not be shrilling you could not be shrilling he could not be shrilling we could not be shrilling you could not be shrilling they could not be shrilling
Perfect	V-ing perfect
I could not have shrilled you could not have shrilled he could not have shrilled we could not have shrilled you could not have shrilled they could not have shrilled	I could not have been shrilling you could not have been shrilling he could not have been shrilling we could not have been shrilling you could not have been shrilling they could not 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
could I not shrill? could you not shrill? could he not shrill? could we not shrill? could you not shrill? could they not shrill?	could I not be shrilling? could you not be shrilling? could he not be shrilling? could we not be shrilling? could you not be shrilling? could they not be shrilling?
Perfect	V-ing perfect
could I not have shrilled? could you not have shrilled? could he not have shrilled? could we not have shrilled? could you not have shrilled? could they not have shrilled?	could I not have been shrilling? could you not have been shrilling? could he not have been shrilling? could we not have been shrilling? could you not have been shrilling? could they not have been shrilling?