Offering your seat
What it really means
On buses and trains it's polite to offer your seat to elderly people, pregnant women, disabled passengers, or anyone who clearly needs it more. Priority seats are marked for this. A simple "Would you like to sit down?" works. Be a little careful — some people may not want to be treated as old, so offer lightly and don't insist.
Context, tips & common mistakes
Offer your seat to anyone who visibly needs it more — and do it in the low-key British way: catch their eye, half-rise, "would you like to sit down?" If they decline, accept the refusal immediately and gracefully; insisting turns kindness into a scene, and some people decline precisely because they do not want attention. Standing up and simply gesturing at the seat works wordlessly when language feels hard.
The pregnancy trap has a London solution: guessing wrong is mortifying for everyone, which is why TfL issues free 'Baby on board' badges — respond to the badge, or to unambiguous need, rather than speculating about strangers' bodies. If you are offered a seat yourself, take it or decline warmly ('I'm fine, thanks — kind of you'); either is correct, and no further negotiation is expected.