(1)13-15 balanced
(2)Stayman
(3)Lead directing
(4)HHxx or Hxxxx in clubs, no 4 card major, suggestion to play
You are playing with your regular partner so you are on firm ground as to the meaning of partner's calls. Your relevant* choices are:
Pass - So endeth the auction
XX - To Play in 2♣XX
2♦ - Scrambling
2NT - Invite
3NT - To Play
*This may be debated for some of the calls above, but trust me that there are more that are irrelevant for sure.
1NT(1) - (P) - 2♣(2) - (X)(3)
P(4) - (P) - ?