Partner opens 1D with a minimum point count and 5 spades you bid 1S partner shows support with a 2S bid but you are minimum so - All Pass
Acol Bidding
Partner opens 1NT - with less than 11 HCP and with a 5 card spade suit you make a sign off bid of 2S (when you respond to 1NT opening with a sign off bid your partner must pass). All Pass
Plan Before You Play
Count your losers 2 in spades 2 in hearts 1 in diamonds and 1 in clubs. Your best chances for reducing the spade and diamond losers is to finesse in both of these suits.
The Play
AH, KH lead - win with QH, play trumps losing to AS win the club return and lead a second round of trumps. from the table, do not finesse on the second round of trumps dropping the QS. With 9 cards in a suit you can usually drop the QS. Play KD and then 10D covering QD with the AD.
Comment
This is another one of those frustrating hands where you only have 21 HCP points and should be in part game but... 10 tricks in spades can be made.
The above commentary is intended as a guideline only. As with any Bridge hand there are many ways to bid and play any hand.