Vietnamese. Some speak French and English.
Vietnamese cuisine is similar to Chinese, with lots of noodles and rice. Buy a breakfast soup called 'pho' from street stalls and don't miss the chance to try a delicious spring roll. On the coast you'll find lots of seafood and fish.
Tailor shops will make bespoke garments for you in no time. You'll find handicrafts such as bamboo items, lacquerware, ceramics, silk and jewellery. Antiques are available, but can be difficult to take back to the UK due to problems at customs. Be sure to haggle for the best price, except in state-run stores where prices are fixed.
A service charge is usually included in the bill in large hotels and restaurants. In small restaurants and bars, leave a tip for good service. You should also tip baggage porters, drivers and guides.