I have made an update to the post καίγε in Joel 2:29 and Acts 2:18, which interacts briefly with Steve Runge’s comments on Acts 2:18.
I post the Update here as well:
UPDATE: Brian Davidson informed me that Steve Runge wrote a paper on Joel 3:1-5 in Acts 2. Steve gives a great discussion of the Hebrew discourse function of גם and the Greek discourse function of γε. The particles גם and γε disambiguate the intended function of the following prepositional phrases marking the fullest extent to which the outpouring of the Spirit will be experienced. The LXX is ambiguous with καί only, but γε in Acts 2:18 indicates that the fronting of the prepositional phrases is emphatic and not contrastive. Excellent analysis of the grammar. What Steve does not mention (not the intention of this paper) is the καίγε tradition, which probably influences Acts 2:18. Before Acts 2, the Jews were already revising גם/וגם with καίγε where the OG had only καί. Therefore, καί γε is not an adaptation on the part of Luke (Steve does not actually suggest this from what I read), rather Luke received a text with καίγε in all probability.
Let’s keep the discussion going.