Started asking translates a Greek verb tense which suggests that the disciples were discussing this question among themselves rather than that they merely asked it once.

The question involves a matter of possibility. It may be translated in some languages “Is it possible that someone has brought food to him?” It is not the ability of someone to do it, as suggested by could, but rather, the possibility, or even the probability, of its having happened. The response is typical of the way this Gospel describes the initial misunderstanding of Jesus’ statements, and then the receiving of a fuller and more spiritual explanation.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .