Jesus asked the Father to send another helper, the Holy Spirit.

The Holy Spirit is "another" like Jesus.  The Holy Spirit is a person; the Holy Spirit is deity.

The Holy Spirit is the Spirit of truth.  The Holy Spirit teaches us.  The Holy Spirit convicts us of sin and draws us to Jesus so that we might be born again.

The Holy Spirit also sanctifies believers, convicting us of sin so that we might become more Christ-like.