A.T. Robertson Commentary John 16:19

"Jesus perceived that they were desirous to ask him, and he said unto them, Do ye inquire among yourselves concerning this, that I said, A little while, and ye behold me not, and again a little while, and ye shall see me?" — John 16:19 (ASV)

Jesus perceived (εγνω Ιησους). Second aorist active indicative of γινωσκω.

That they were desirous to ask him (οτ ηθελον αυτον ερωταιν). Imperfect active tense of θελω in indirect discourse instead of the retention of the present θελουσιν (the usual idiom), just like our English. Their embarrassment was manifest after four inquiries already (Peter, Thomas, Philip, Judas). So Jesus takes the initiative.