[inquiry]

I am not sure this auction is possible...

 P - (P) - 1D - (1S)
2H -(P) - 3C - (P)
3H

Since partner CAN NOT have hearts good enough to bid twice on this auction, I don't play him to have those kind of hearts. If he was an unpassed hand, I would pass 3♥.

1) Partner did not open 2H, nor 3H and yet has a good enough hand to not make a negative double and then rebid hearts. But rather to bid 2H and then 3H. This is clearly at least six if not 7 hearts. Perhaps I am playing with one of those people who will not preempt in one major despite holding a very weak four card side major? (after all, how strong can his spades be with you having AJ9)? But in that case, he should have stuck with negative double, then bid hearts.

2) If your partner would not bid this way with 4-6-(21) or 4-7-(20) etc, then you must accept the 3♥ bid as a fit for one of the minors and is a game try. No other explaination makes sense to me (see why I lose all the time).

I would probably just bid 5♣ and let partner pick the contract, but given that 5♣ is not an option, I will try 3♠ planning on bidding 4♣ over 3NT.

Needless to say I am all wrong, and my 5♣ is going to lead to -1400 but nothing else makes any sense other than partner has a minor fit and is relying on me to work it out. Something like (not the well placed ten of diamonds!).

S-x
H-Axxxxx
D-QT
C-KJxx

If your partner opens that 2♥, remove a heart and add a spade.