In other words, it can take cyclic movement which consists of QR followed by wh-movement.
when we suppose that examples like (4) in English are genuine multiple sluicing which is derived by deleting a TP after multiple wh-fronting occurs out of it, an immediate problem facing us is why the example without TP deletion as in (6) is ungrammatical: (6) *They didn't tell me [which] [for which] got something The following pair also makes the same case.