A.T. Robertson Commentary 1 John 2:27

"And as for you, the anointing which ye received of him abideth in you, and ye need not that any one teach you; but as his anointing teacheth you; concerning all things, and is true, and is no lie, and even as it taught you, ye abide in him." — 1 John 2:27 (ASV)

And as for you (κα υμεις). Prolepsis again as in verse 24.Which ye received of him (ο ελαβετε απ' αυτου). Second aorist active indicative of λαμβανω, a definite experience, this anointing (χρισμα), from Christ himself as in verse 20. This Paraclete was promised by Christ (John 14:26; 16:13ff.) and came on the great Pentecost, as they knew, and in the experience of all who yielded themselves to the Holy Spirit.

That any one teach you (ινα τις διδασκη υμας). Sub-final use of ινα and the present active subjunctive of διδασκω, "that any one keep on teaching you."

Teacheth you (διδασκε υμας). Present active indicative. The Holy Spirit was to bring all things to their remembrance (John 14:26) and to bear witness concerning Christ (John 15:26; John 16:12–15). Yet they need to be reminded of what they already know to be "true" (αληθες) and "no lie" (ουκ εστιν ψευδος), according to John's habit of positive and negative (1:5). So he exhorts them to "abide in him" (μενετε εν αυτω, imperative active, though same form as the indicative). Precisely so Jesus had urged that the disciples abide in him (John 15:4f.).