Too many questions nagged at me; so much was at risk.

But a question still nagged: What did it mean?

A further question nagged him, although it had nothing to do with his research-directly.

He spoke English well, but a question still nagged.

On the other hand, I had to admit that several unanswered questions nagged at me.

The question must have nagged at Johnson for years.

Mackenzie didn't call him back, but his question nagged at her.

Such questions had nagged at him for much of his life.

That question would nag at him as long as he lived.

The same questions have nagged the developing body of art law for years.