From the beginning of the novel "The Grove", what does the る mean in
検非違使に問われた る 木樵りの物語
問われた is the passive of 問う, but where does the る come from? Is it the short form of いる?
It is the completive particle -tar in attributive form.
The past suffix -ta, which we are familiar with, is from the suffix tar-. tar- conjugates:
Other than -naru, modern Japanese does not distinguish between conclusive and attributive anymore. But originally conclusive was used to end a sentence. A period followed it. The attributive was used when a phrase followed after it.
In this sentence, the noun phrase 木樵りの物語 follows 問われた, so the attributive form is necessary. In classical Japanese, this would be 問われたる. If it were 問われたり, the sentence would just end there. The following 木樵りの物語 would be the start of a new sentence.