An opening bid at the two-level shows
(a) 6-10 HCP
(b) five card suit in the bid suit
(c) a four card side suit (includes other major if a major is bid).
Response:
(a) 2S to play spades if opened 2H
(b) 2NT = play in other suit
(c) LNew suit = to play.
(d) 3 of opening suit invitational
(e) Bid game in suit opened