But I had to use a knife to cut out her heart.
He used the knife to let some blood from his arm.
Was the answer to use the knife or to leave it?
He couldn't use the knife: they were all moving too quickly.
If they try to catch me, I will use the knife.
She'd never even been taught how to use a knife.
The police do not know why he used a knife rather than a gun.
And if his arms were tied, how did he use the knife?
Sometimes I'd use the knife to get the doors open.
"Where did you learn to use a knife like that?"