Meaning of として in this sentence I don't get why is used instead of in this sentence, as it doesn't seem to fit with the "as" sense that I know. > **** What I understand is this: > Treating as a group, regardless of their part of speech, is common. Thinking while writing: I was assuming that was related to . But if instead it is related to then Y would mean by grouping them as Y. Which would mean that something like would be omitted in the sentence > > It is common to treat ( and ) by grouping them together as . Am I correct?

Assuming that the phrase was taken from this page, the use of is 100% correct and natural.

You cannot use in place of because the direct object of that sentence is NOT . It is []{}[]{} or more formally and appropriately in this context, []{}, which was omitted.

Thus, it is talking about "treating (demonstratives and interrogatives) by lumping them together as independently of parts of speech."

You were correct in sensing that a word was being omitted.