It took me too long to come up with the correct response."Don't tell me you're listening to Billy'ssuperstitious nonsense now," I said with a feeble attempt at mockery."He knows more than I gave him credit for.""Be serious,Jacob."credit for
问题描述：
It took me too long to come up with the correct response."Don't tell me you're listening to Billy's
superstitious nonsense now," I said with a feeble attempt at mockery.
"He knows more than I gave him credit for."
"Be serious,Jacob."
credit for
答
give credit for 本意是归功于.../认证...的功劳 的意思。在这句话里可以理解为“知道的多过我所认可的”或者是“多过我认为他应该知道的”（即有一些并不是真的知道）
答
to give somebody credit for 是个短语,本意是为某人提供信用贷款,这里用的他的延伸含义,意思是：相信某人有（某种优点）
根据这里的上下文,
"He knows more than I gave him credit for." 可以翻译为：
我相信他知道得确实很多.