Hat tip to Gary Yates (via Twitter) for reminding me of this 2003 article by noted Greek grammarian Dan Wallace:

Daniel B. Wallace, “Greek Grammar and the Personality of the Holy Spirit,” Bulletin for Biblical Research 13 (2003): 97-126.

Here’s the abstract:

The modern, broadly conservative articulation of the distinct personality and deity of the Holy Spirit has often included in its arsenal a point or two from the realm of philology. The Fourth Gospel has especially been mined for such grammatical nuggets, though Ephesians, 1 John, and sometimes even 2 Thessalonians have been claimed as yielding syntactical evidence in defense of the Spirit’s personality. Two kinds of texts have been put forth in support of this supposition: passages involving grammatical gender and passages involving notions of agency. Those involving grammatical gender are used as an apologetic defense of a high pneumatology; those involving agency are simply assumed to prove the point. I believe that this grammatical defense for the Spirit’s personality has a poor foundation. If it is indeed invalid, then to use it in defense of a high pneumatology not only damages Trinitarian apologetics but also may well mask an emerging pneumatology within the NT.

Coming from Wallace, it’s no surprise that this is a very good article. You’ll need some knowledge of Greek to follow it completely. As those who have read my “Myth book” draft may recall, my own thinking about the doctrine of the Trinity does not derive from grammar.