“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"
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.