"And I (Jesus) will pray (to) the Father, and He will give you another Helper,
that He may abide with you forever -- the Spirit of truth
… you know Him, for He dwells with you and will be in you.
I will not leave you orphans; I will come to you.
… If anyone loves Me, he will keep My word; and My Father will love him,
and We will come to him and make Our home with him.
… But the Helper, the Holy Spirit, whom the Father will send in My name,
He will teach you all things, and bring to your remembrance all things that I said to you."
The Greek word here for "another" is "allos" meaning "another of the same kind" (ref: Vine).
So, the Holy Spirit is another Person of the Triune Godhead (like God the Son).
It seems to say that ...
all 3 Persons of the Triune God will come to be with the faithful believer,
but only the Holy Spirit will remain in him/her forever (i.e. until death),
and only the Holy Spirit will be the One doing the teaching.