Here’s a series of bridge questions for you. If your left-hand opponent opens the bidding in one of a suit, your partner overcalls in another suit, and your right-hand opponent passes, you get a special name in bridge terminology. You’re the “advancer.” You have these choices:

     • Pass
     • Raise partner
     • Bid a new suit
     • Bid any level of NoTrump
     • Cuebid opener’s suit
     • Make a jump bid in a new suit

Of these choices, only 1) an unlikely 4NT (given West’s opening bid, 2) jumping in a new suit, and 3) cuebidding opener’s suit are forcing. That’s right: introducing a new suit at the lowest possible level is not forcing!

In one case, you hold these cards:
     ♠️ A K 6
     ♥️ 10 9 2
     ♦️ 10 9 8 7 6
     ♣️ 3 2

Here’s the bidding:

LHO          PART          RHO          YOU
1 ♥️          1♠️               Pass            ?

A simple 2♠️ will do nicely.

In another case, you hold:

     ♠️ A K J
     ♥️  Q J 10
     ♦️ 9 8 7 6
     ♣️  4 3 2

LHO          PART          RHO          YOU
1♥️           1♠️              Pass            ?

Cuebid 2 ♥️. This bid is at first ambiguous. Partner should assume it’s a limit raise+ bid in support of spades. If you meant something else, you’ll correct with your next bid.
In a final test case, you hold:

     ♠️ A J
     ♥️ Q J 10
     ♦️ 9 8 7 6
     ♣️ 5 4 3 2

LHO          PART          RHO          YOU
1♥️           1♠️               Pass            ?

Bid 1NT. Since partner may have made a light overcall, 1NT should show 8-10 high-card points and at least one stopper in LHO’s suit.
In this hand from Internet bridge, West is dealing, with no one vulnerable:

                                          NORTH
                                         ♠️ A K J 9 8 5
                                         ♥️ 10 9 4
                                         ♦️ 2
                                        ♣️ A 9 8
WEST                                                                   EAST
♠️ 10 3                                                                ♠️ Q 7 6 2
♥️  K Q                                                               ♥️ 5 3
♦️ A J 10 6 4 3                                                   ♦️ 9 8 5
♣️ K 5 4                                                             ♣️ Q 7 3 2

                                      SOUTH
                                     ♠️ 4
                                     ♥️ A J 8 7 6 2
                                     ♦️ K Q 7
                                     ♣️ J 10 6


The bidding proceeded as follows:
West          North          East          South
1♦️            1♠️               Pass          3 ♥️
Pass          4 ♥️              All Pass
Opening lead: ♠️10

South made the bid, with single losers in hearts, diamonds and clubs.