I am no expert in New Testamanet Greek either but can offer you the following on John 15:26 ""But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of Truth, which proceedeth from the Father, he shall testify of truth." In the Greek the word rendered 'whom' is masculine, the word rendered 'which' is neuter and the word rendered 'he' is masculine. Thus "But when the Comforter is come, whom [masculine] I will send unto you from the Father, even the Spirit of Truth, which [neuter] proceedeth from the Father, he [masculine] shall testify..."
If the Holy Spirit was an impersonal force and not a person then I would expect only neuter language and no masculine terminology. Given the mystery (something beyond human understanding) of the Godhead and that even terms such as Father and Son though masculine do not actually indicate maleness according to human concepts (for God is spirit) then it does not surprise me to find both masculine and neuter terminology used about the Holy Ghost.
A valuable resource is St Basil the Great's "On the Holy Spirit" (available I believe in a number of editions).